# GCN_circulars

GRB_name: GRB240225B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35798
SUBJECT: GRB 240225B: AstroSat CZTI detection
DATE:    24/02/26 09:04:31 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240225B which was also detected by MAXI/GSC (M. Nakajima et al., GCN Circ. 35796). Inspection of INTEGRAL/SPI-ACS data also showed the detection of the burst. We note that the INTEGRAL/SPI-ACS detection time is consistent with our time which is about 3 min offset from the time reported in the MAXI/GSC detection (GCN 35796). 

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-02-25 20:12:08.50 UTC. The measured peak count rate associated with the burst is 185 (+40, -22) counts/s above the background in the combined data of all quadrants, with a total of 1617 (+331, -224) counts. The local mean background count rate was 346 (+1, -5) counts/s. Using cumulative rates, we measure a T90 of 19 (+10, -5) s.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-02-25 20:12:01.80 UTC. The measured peak count rate associated with the burst is 570 (+72, -69) counts/s above the background in the combined data of all quadrants, with a total of 5119 (+490, -666) counts. The local mean background count rate was 1539 (+7, -6) counts/s. We measure a T90 of 23 (+3, -4) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240225C
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35799
SUBJECT: GRB 240225C: AstroSat CZTI detection
DATE:    24/02/26 09:10:37 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240225C which was also detected by Calet (Trigger Num. 1392873321), INTEGRAL/SPI-ACS (Trigger Num. 10590), and Konus-WIND (IPN RAW notices).

The source was detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-02-25 05:19:38.80 UTC. The measured peak count rate associated with the burst is 289 (+71, -45) counts/s above the background in the combined data of all quadrants, with a total of 1297 (+320, -349) counts. The local mean background count rate was 1387 (+7, -7) counts/s. We measure a T90 of 6.7 (+2.6, -1.6) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240222A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35801
SUBJECT: GRB 240222A: ATCA radio observations
DATE:    24/02/26 17:22:04 GMT
FROM:    jamesk.leung@utoronto.ca

J. K. Leung (U. Toronto/HUJI), G. E. Anderson (Curtin University),
S. Chastain (UNM), A. Gulati (U. Sydney), L. Rhodes (U. Oxford),
A. J. van der Horst (GWU) on behalf of the PanRadio GRB collaboration

The Australia Telescope Compact Array (ATCA) performed observations
of GRB 240222A (Fermi GBM Team, GCN 35769; D'Avanzo et al., GCN 35770)
at 5.5, 9, 16.7 and 21.2 GHz as part of the Large ATCA "PanRadio GRB"
follow-up programme C3542 (PI. Anderson). ATCA observed from
2024-02-24 12:00 UT to 22:00 UT. In our preliminary analysis, we find
no radio source coincident with the refined XRT position (Beardmore
et al., GCN 35780) with 3 sigma upper limits of 75, 54, 69 and 159
microJy/beam at 5.5, 9.0, 16.7 and 21.2 GHz, respectively.

We thank the CSIRO Space and Astronomy staff for supporting these
observations. We acknowledge the Gomeroi people as the traditional
owners of the Observatory site. The Australia Telescope Compact Array is
part of the Australia Telescope National Facility
(https://ror.org/05qajvd42) which is funded by the Australian Government
for operation as a National Facility managed by CSIRO.


GRB_name: GRB240225C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35802
SUBJECT: GRB 240225C: GRBAlpha detection
DATE:    24/02/26 18:27:13 GMT
FROM:    Jakub Ripa <ripa.jakub@gmail.com>

J. Ripa, M. Dafcikova, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The long-duration GRB 240225C (AstroSat detection: GCN 35799; CALET/CGBM detection: trigger no. 1392873321; INTEGRAL/SPI-ACS detection: trigger no. 10590) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract).

The detection was confirmed at the peak time 2024-02-25 05:19:36.5 UTC. The T90 duration measured by GRBAlpha is 8.5 s and the overall significance during T90 reaches 5.5 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240225C_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.


GRB_name: GRB240226A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35804
SUBJECT: GRB 240226A: Fermi GBM Final Real-time Localization
DATE:    24/02/26 19:43:46 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 19:33:07 UT on 26 Feb 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240226A (trigger 730668792.323378 / 240226815).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 289.1, Dec = -43.1 (J2000 degrees, equivalent to J2000 19h 16m, -43d 06'), with a statistical uncertainty of 9.0 degrees.

The angle from the Fermi LAT boresight is 30.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240226815/quicklook/glg_skymap_all_bn240226815.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240226815/quicklook/glg_healpix_all_bn240226815.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240226815/quicklook/glg_lc_medres34_bn240226815.gif


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35805
SUBJECT: GRB 240225B: GOTO detection of a candidate optical afterglow
DATE:    24/02/26 20:45:40 GMT
FROM:    Ben Gompertz at U of Birmingham <b.gompertz@bham.ac.uk>

B. P. Gompertz, R. L. C. Starling, M. Kennedy, G. Ramsay, D. B. Malesani, B. Godson, K. Ackley, M. J. Dyer, J. Lyman, K. Ulaczyk, F. Jimenez-Ibarra, A. Kumar, D. O'Neill, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Pall'e and D. Pollacco report on behalf of the GOTO collaboration:

We report on observations of the MAXI-discovered GRB 240225B (Nakajima et al, GCN 35796) with the Gravitational-wave Optical Transient Observer (GOTO, Steeghs et al. 2022). GOTO-North serendipitously tiled the MAXI localisation at 21:45:51 UT on 2024-02-25, 1.5 hours after trigger. The observation consisted of 4x45 s exposures in the GOTO L-band (400-700 nm).

Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using recent survey observations of the same pointings. Source candidates were initially filtered using a classifier (Killestein et al. 2021) and cross-matched against a variety of contextual and minor planet catalogues. Human vetting was carried out in real time on any candidates that passed the above checks.

We identify a new optical source (GOTO24tz/AT2024dgu) with a magnitude of L = 17.12 +/- 0.04 at RA 08:33:26.67, Dec +27:04:32.71 (J2000). The optical source is close to the probable X-ray afterglow identified in tiled Swift observations (Evans, GCN 35797), offset by 7.2â€, whilst formally outside the 4.4â€ 90% confidence contour of the X-ray localisation. This source was not present in the previous GOTO epoch, taken one day prior at 22:05:36 UT on 2024-02-24, to a limiting magnitude of L > 18.7. Given the tight pre-burst limit and close proximity with a new X-ray source, we propose this as a strong candidate afterglow of GRB 240225B.

Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction.

GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC).


GRB_name: GRB240225C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35806
SUBJECT: GRB 240225C: CALET Gamma-Ray Burst Monitor detection
DATE:    24/02/26 20:51:06 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

S. Sugita , A. Yoshida, T. Sakamoto (AGU), Y. Kawakubo (LSU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 240225C (INTEGRAL SPI ACS Trigger: Trigger Num. 10590;  
IPN RAW NOTICE (KONUS/Wind);  AstroSat CZTI detection: Joshi et al., 
GCN Circ. 35799; GRBAlpha detection: Ripa et al., GCN Circ. 35802) 
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 05:19:32.73
UTC on 25 February 2024
(http://cgbm.calet.jp/cgbm_trigger/flight/1392873321/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a single pulse that starts
at T+2.6 sec, peaks at T+4.2 sec, and ends at T+22.6 sec.
The T90 and T50 durations measured by the SGM data are 13.1 +/- 3.4 sec
and 4.6 +/- 0.4 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1392873321/index.html

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB240226B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35809
SUBJECT: GRB 240226B: Fermi GBM Final Real-time Localization
DATE:    24/02/26 21:41:00 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 05:40:04 UT on 26 Feb 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240226B (trigger 730618809.579832 / 240226236).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 353.7, Dec = -24.4 (J2000 degrees, equivalent to J2000 23h 34m, -24d 23'), with a statistical uncertainty of 5.4 degrees.

The angle from the Fermi LAT boresight is 100.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240226236/quicklook/glg_skymap_all_bn240226236.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240226236/quicklook/glg_healpix_all_bn240226236.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240226236/quicklook/glg_lc_medres34_bn240226236.gif


GRB_name: GRB240225B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35810
SUBJECT: GRB 240225B: Swift-XRT observations
DATE:    24/02/26 22:22:37 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB),
J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester) and P.A. Evans (U.
Leicester) and A. A. Breeveld (UCL-MSSL) reports on behalf of the
Swift-XRT and the Swift-UVOT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 240225B in a series of observations tiled on the sky. The
total exposure time is 1.8 ks, distributed over 7 tiles; the maximum
exposure at a single sky location was 693 s. The data were collected
between T0+29.1 ks and T0+30.9 ks, and are entirely in Photon Counting
(PC) mode. 

Two uncatalogued X-ray sources are detected, of which one ("Source 1")
is above the RASS 3-sigma upper limit at this position. The position of
this source is RA, Dec=128.3629, +27.0746 which is equivalent to:

RA (J2000): 08:33:27.11
Dec(J2000): +27:04:28.5

with an uncertainty of 4.4 arcsec (radius, 90% confidence).  This
position is 25.3 arcmin from the MAXI position. At the present time the
light curve of Source 1 shows no signs of fading and we can not 
confirm this source as the GRB afterglow.

The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00124.

Source 1 was out of the field of view for UVOT so we can't say anything
about optical properties.

This circular is an official product of the Swift team.


GRB_name: GRB240225B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35811
SUBJECT: GRB 240225B: CALET Gamma-Ray Burst Monitor detection
DATE:    24/02/26 22:35:56 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

Y. Kawakubo (LSU), A. Yoshida, T. Sakamoto, S. Sugita (AGU), 
K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 240225B (MAXI/GSC detection: Nakajima et al., 
GCN Circ. 35796; AstroSat CZTI detection: Joshi et al., 35798)
was detected in the ground analysis of the CALET Gamma-ray 
Burst Monitor (CGBM) data around 20:12:08.50 on 25 February 
2024 (referenced to the AstroSat detection: GCN Circ. 35798)
(http://cgbm.calet.jp/cgbm_trigger/flight/1392926875/index.html).
The main episode that AstroSat CZTI detected was seen by all CGBM 
detectors. Also, a hint of emission that MAXI/GSC detected was seen 
in the HXM data around T+230 s.

The burst light curve of the main episode shows a multi-peaked 
structure that starts at T-7.6 sec, and ends at T+31.1 sec. The T90 
and T50 durations measured by the SGM data are 33.0 +/- 0.9 sec
and 17.1 +/- 1.3 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1392926875/index.html

The CALET data used in this analysis are provided by 
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35812
SUBJECT: GRB 240225B: Nanshan/HMT optical afterglow detection
DATE:    24/02/26 23:18:55 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

X. Liu,, J. An, S.Y. Fu, S.Q. Jiang, Z.P. Zhu, T.H. Lu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:

We observed the field of GRB 240225B detected by MAXI (Nakajima et al., GCN 35796) and AstroSat (Joshi et al., GCN 35798) using the HMT-0.5m telescope with big FOV (~1 deg^2) located at Nanshan, Xinjiang, China. Photometry was carried out twice in the same night without any filter..

A slowly decaying uncatalogued optical transient is detected at coordinates

R.A. = 08:33:26.80 (J2000)
Dec. = +27:04:32.77 (J2000)

with an uncertainty of radius ~ 0.3 arcsec, with r ~ 18.9 +/- 0.1 mag (AB) at a median time of 18.90 hr post-burst, calibrated with the nearby PanSTAR field. This OT is positionally at the border of the error circle of Swift/XRT  "Source 1" (D'Ai  et al., GCN 35810), and is also consistent with and thus confirming the GOTO candidate (Gompertz et al., GCN 35805).

We thus think the OT is the optical afterglow of GRB 240225B.


GRB_name: GRB240226B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35813
SUBJECT: Fermi Gamma-ray Burst Monitor trigger 730618809/240226236 is not a GRB
DATE:    24/02/27 00:17:45 GMT
FROM:    Lorenzo Scotton at UAH <lscottongcn@outlook.com>

L. Scotton (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

"The Fermi Gamma-ray Burst Monitor (GBM) trigger 730618809/240226236 at 05:40:04.58 UT
on 26 February 2024 was initially classified as a GRB, and named GRB 240226B (GCN 35809).
This trigger is in fact not due to a GRB, but to a solar flare."


GRB_name: GRB240227A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35814
SUBJECT: GRB 240227A: Fermi GBM Final Real-time Localization
DATE:    24/02/27 04:48:09 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 04:40:15 UT on 27 Feb 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240227A (trigger 730701620.164308 / 240227195).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 69.6, Dec = -61.2 (J2000 degrees, equivalent to J2000 04h 38m, -61d 12'), with a statistical uncertainty of 3.6 degrees.

The angle from the Fermi LAT boresight is 13.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240227195/quicklook/glg_skymap_all_bn240227195.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240227195/quicklook/glg_healpix_all_bn240227195.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240227195/quicklook/glg_lc_medres34_bn240227195.gif


GRB_name: GRB240218A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35818
SUBJECT: GRB 240218A: CMO SAI NIR upper limit
DATE:    24/02/27 12:04:54 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Pozanenko (IKI), B. Safonov (SAI MSU),  A. Tatarnikov (SAI MSU), N. Pankov (HSE, IKI),  S. Belkin (IKI, HSE) report on behalf of IKI-GRB-FuN: 

We observed the field of GRB 240218A (Page et al., GCN 35742;  Veres et al., GCN 35755; Svinkin et al., GCN 35758) with the Astronomical Near-Infrared Camera-spectrograph (ANC) of the 2.5-meter telescope (SAI-2.5) of the Caucasian Mountain Observatory (CMO SAI) on Feb.23, 2024 starting on 22:16:46 UT, taking 47 frames of 1-minute exposure in the H-band under moderate conditions with seeing of 1.4". We do not detect the NIR counterpart (D'Avanzo et al., GCN 35747; Saccardi et al., 35756; Schroeder et al., GCN 35794; Rossi et al., GCN 35762; de Wet et al., GCN 35765) within the enhanced XRT error box (Evans et al., GCN 35748). 
Preliminary photometry of the stacked image is following

Date       UT start   t-T0     Filter  Exp.    OT     UL(3sigma)
                      (mid, days)  (s)
2024-02-23 22:16:46   5.86743  H       47*59   n/d    20.8   

The photometry is based on nearby 2MASS stars:

2MASS_ID         RA              Dec           H      errH
10471145+0118146 10:47:11.45808 +01:18:14.6268 15.422 0.098
10471594+0117439 10:47:15.94200 +01:17:43.9836 14.562 0.062
10471583+0116464 10:47:15.83136 +01:16:46.4844 14.243 0.045


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35819
SUBJECT: GRB 240225B: NOT optical observations
DATE:    24/02/27 12:24:03 GMT
FROM:    Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl>

D. B. Malesani (DAWN/NBI and Radboud Univ.), B. P. Gompertz (Birmingham), Z.-P. Zhu, D. Xu (NAOC), L. Izzo (INAF/OACN and DARK/NBI), on behalf of a larger collaboration, and R. Forsberg (Lund), S. Bijavara Seshashayana (Malmo univ.), report:

We observed the optical afterglow (Gompertz et al., GCN 35805; D'Ai et al., GCN 35810) of GRB 240225B (Nakajima et al., GCN 35796; Joshi et al., GCN 35798; Kawakubo et al., GCN 35811). We used the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started on 2024 Feb 26.934 UT (1.09 days after the MAXI trigger time).

In a single 300-s exposure in the r band, we measure r = 19.53 +- 0.03 (AB), calibrated against nearby Pan-STARRS stars.

This confirms the decay of the GOTO candidate noted by Liu et al. (GCN 35812). Assuming an unbroken power law decay (F propto t^-alpha) between their observation and ours, the inferred decay slope is alpha = 1.8 +- 0.3, suggesting a faster decay then indicated in Liu et al. (GCN 35812).


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35820
SUBJECT: GRB 240225B: Liverpool Telescope optical afterglow observations
DATE:    24/02/27 16:49:48 GMT
FROM:    Jacob Wise at Liverpool John Moores University <J.L.Wise@2022.ljmu.ac.uk>

J. Wise, A. Bochenek, D. A. Perley (LJMU) report:

We report observations the optical afterglow GOTO24tz/AT2024dgu (Gompertz et al, GCN 35805; D'Ai et al, GCN 35810; Xu, D., GCN 35812; Malesani et al, GCN 35819) associated with GRB 240225B (Nakajima et al, GCN 35796; Joshi et al, GCN 35798; Kawakubo et al, GCN 35811) using the IO:O optical camera on the 2-meter Liverpool Telescope. Observations commenced at 2024-02-27 00:20:06.433 UTC, approximately 28.1 hours after the burst. 2x75s exposures were taken using the SDSS g, r, i, and z filters, with Pan-STARRS foreground stars used for calibration. Conditions were generally favourable throughout. 

The transient was well detected in all 4 filters, with magnitudes listed in the following table. Times since burst for each filter were calculated using the strongest peak found with the AstroSat CsI anticoincidence (Veto) detector as reference (Joshi et al, GCN 35798).

MJD         Time since burst (hours) Filter Mag. (AB)
60367.01396 28.135                         g 19.97 Â± 0.12
60367.01624 28.189                         r 19.51 Â± 0.15
60367.01848 28.243                         i 19.44 Â± 0.10 
60367.02073 28.297                         z 19.28 Â± 0.14

Magnitudes are not corrected for foreground extinction.


GRB_name: GRB240227A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35821
SUBJECT: IPN triangulation of GRB 240227A (short)
DATE:    24/02/27 16:50:22 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:

The short-duration GRB 240227A
(Fermi-GBM detection: The Fermi GBM team, GCN 35814)
was detected by Fermi (GBM trigger 730701620), Konus-Wind,
and INTEGRAL (SPI-ACS) at about 16815 s UT (04:40:15).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
   18.683 (01h 14m 44s) -34.040 (-34d 02' 23")
 Corners:
   19.224 (01h 16m 54s) -35.743 (-35d 44' 35")
   18.820 (01h 15m 17s) -32.316 (-32d 18' 58")
   18.123 (01h 12m 29s) -32.337 (-32d 20' 15")
   18.499 (01h 14m 00s) -35.765 (-35d 45' 54")
 ---------------------------------------------
The error box area is 2.02 sq. deg, and its maximum
dimension is 3.53 deg (the minimum one is 35 arcmin).
The Sun distance was 43 deg.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240227_T16812/IPN

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.


GRB_name: GRB230824A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35823
SUBJECT: Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up
DATE:    24/02/27 19:08:13 GMT
FROM:    Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>

TITOLO: Swift J1727.8-1613 (GRB 230824A): Madrona Peak Observatory - optical follow-up

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione.
report:

Following the Swift trigger no. 1186959 (GCN 34537), using the 24 Inch RC Optical Ritchey-Chretien Reflector telescope and the Apogee Aspen CG16M camera of the Madrona Peak Observatory connected to the AAVSONet network,
we obtained a series of B,V,R images of the transient approximately 6 months after the first detection. 
The images were measured with the VPhot AAVSO software, using the APASS catalogue. The photometry obtained on 19/23/25 February 2024 are as follows:

with the following photometry:

    JD            Mag         Filter
2460363.97895 15.830            V
2460363.97781 15.987            V
2460359.99249 15.864            V
2460359.99139 15.837            V

 


JD           Mag        Filter
2460365.97083 15.713            R
2460363.98126 15.552            R
2460363.98014 15.535            R
2460359.99473 15.530            R
2460359.99362 15.512            R



JD           Mag        Filter
2460363.97611 15.230            B
2460363.97427 16.275            B
2460359.98979 16.096            B
2460359.98799 16.131            B




The magnitudes are calibrated with stars of the APASS catalog are not corrected for the expected Galactic extinction.

The message may be cited.


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35824
SUBJECT: GRB 240225B: Liverpool Telescope afterglow observations
DATE:    24/02/28 00:26:44 GMT
FROM:    Ben Gompertz at U of Birmingham <b.gompertz@bham.ac.uk>

B. P. Gompertz (U. Birmingham), D. B. Malesani (DAWN/NBI and Radboud Univ.) report:

We observed the position of the optical afterglow (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820) of GRB 240225B (Nakajima et al., GCN 35796; Joshi et al., GCN 35798; Kawakubo et al., GCN 35811) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations began at 21:37:18 on 2024-02-27, 2.06 days after trigger, and consisted of 15x120 s exposures in the SDSS r filter.

We detect the afterglow with an AB magnitude of r = 20.04 +/- 0.05, calibrated against nearby SDSS stars and not corrected for foreground extinction. Between this epoch and the initial detection by GOTO (Gompertz et al., GCN 35805), the afterglow is well described by a power-law decay with an index of 0.8, which is consistent with the magnitudes reported by NOT (Malesani et al., GCN 35819) and LT (Wise et al., GCN 35820), though under-predicts those reported by Nanshan/HMT (Liu et al., GCN 35812), potentially suggestive of flaring behaviour at the time of their observation. The steepening in the light curve noted in GCN 35819 may be thus due to local variability, rather than a break in the power-law evolution.

We note the presence of a faint underlying source at the afterglow position in Legacy Survey archival imaging, which may be the host galaxy of GRB 240225B.


GRB_name: GRB240227A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35825
SUBJECT: Fermi GRB 240227A: Global MASTER-Net observations report
DATE:    24/02/28 04:30:39 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240227A ( Fermi GBM team, GCN 35814) errorbox  48100 sec after notice time and 48133 sec after trigger time at 2024-02-27 18:02:28 UT, with upper limit up to  18.0 mag. Observations started at twilight.  The observations began at zenith distance = 32 deg. The sun  altitude  is -10.2 deg. 

The galactic latitude b = -39 deg., longitude l = 271 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2387115

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   48163 | 2024-02-27 18:02:28 |         MASTER-SAAO | (04h 37m 02.73s , -61d 29m 49.8s) |   C |    60 | 17.6 |        
   48163 | 2024-02-27 18:02:28 |         MASTER-SAAO | (04h 55m 01.13s , -61d 40m 45.7s) |   C |    60 | 17.3 |        
   48243 | 2024-02-27 18:03:47 |         MASTER-SAAO | (04h 21m 16.28s , -59d 36m 59.5s) |   C |    60 | 17.8 |        
   48243 | 2024-02-27 18:03:47 |         MASTER-SAAO | (04h 38m 13.45s , -59d 47m 57.1s) |   C |    60 | 17.4 |        
   48322 | 2024-02-27 18:05:07 |         MASTER-SAAO | (04h 21m 36.67s , -63d 25m 43.7s) |   C |    60 | 18.0 |        
   48322 | 2024-02-27 18:05:07 |         MASTER-SAAO | (04h 40m 47.01s , -63d 36m 37.9s) |   C |    60 | 17.7 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35826
SUBJECT: GRB 240225B: Mondy afterglow observations
DATE:    24/02/28 07:44:44 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI, HSE) 
report on behalf of IKI-GRB-FuN:

We observed the field of GRB 240225B (Nakajima et al., GCN 35796; Evans, GCN 35797, 
Joshi et al., GCN 35798; D'Ai et al., GCN 35810; Kawakubo et al., GCN 35811) with 
AZT-33IK telescope of Sayan observatory (Mondy) equipped with CMOS-photometer 
ANDOR NEO. We took 60x120 sec frames in the R-filter starting on 2024-02-26 (UT) 
12:30:03. The optical afterglow (Gompertz et al., GCN 35805; Liu et al., GCN 35812; 
Malesani et al., GCN 35819; Wise et al., GCN 35820; Gompertz & Malesani, GCN 35824) 
is well detected in the stacked frame with a total exposure of 59x120 sec. Photometry 
of the optical afterglow is following:

Date       UT-start t-T0    Exp    Filter OT    Err   UL         FWHM
(UT)          (mid.)        (nxT)                   (3sigma)   (arcsec)
2024-02-27 13:01:23 1.71919 59x120 R      19.16 0.09  22.8       2.1

The magnitudes were calibrated using nearby USNO-B1.0 stars (R2 magnitudes).


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35828
SUBJECT: GRB 240225B: SAO RAS optical observations
DATE:    24/02/28 22:16:52 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin, O. I. Spiridonova (SAO RAS)
report on behalf of the GRB follow-up team.

We observed the field of GRB 240225B (Nakajima et al., GCN 35796;
Evans, GCN 35797; Joshi et al., GCN 35798; D'Ai et al., GCN 35810;
Kawakubo et al., GCN 35811) with the SAO RAS 1m telescope Zeiss-1000
equipped with CCD-photometer. We obtained 8 x 300 sec frames in the Rc
band on Feb. 28, 18:20:36--19:11:22 UT (t_mid - T0 = 2.9307 days).

The OT (Gompertz et al., GCN 35805; Liu et al., GCN 35812;
Malesani et al., GCN 35819; Wise et al., GCN 35820;
Gompertz & Malesani, GCN 35824; Pankov et al.,  GCN 35826)
is clearly detected in our stacked frame with the brightness of
R = 20.51 +/- 0.02.

The photometry is based on nearby SDSS stars (magnitudes converted
with Lupton 2005 equations).


GRB_name: GRB240225B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35829
SUBJECT: GRB 240225B: WINTER near-IR observations and upper limits
DATE:    24/02/29 01:10:22 GMT
FROM:    Geoffrey Mo at MIT <gmo@mit.edu>

Geoffrey Mo (MIT), Viraj Karambelkar (Caltech), Danielle Frostig (MIT), Robert Stein (Caltech), Nathan Lourie (MIT), Tomas Ahumada (Caltech), Robert Simcoe (MIT), Mansi Kasliwal (Caltech) report:

We observed the field of GRB 240225B (Nakajima et al., GCN 35796; Evans, GCN 35797; Joshi et al., GCN 35798; D'Ai et al., GCN 35810; Kawakubo et al., GCN 35811) using the Palomar 1-m telescope equipped with the 1-square degree infrared WINTER camera (Lourie et al., 2020) in the Y and J bands. Observations began at 2024-02-28T05:55:09 UTC (~2.4 days after the GRB) and consisted of 8 x 120 s exposures in each filter.

The images were processed using the WINTER data reduction pipeline (https://github.com/winter-telescope/mirar), with J-band image subtraction performed against reference images from the UKIRT Hemisphere Survey (Dye et al., 2017). 

We do not detect the GOTO-discovered counterpart (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820; Gompertz & Malesani, GCN 35824; Pankov et al., GCN 35826; Moskvitin et al., GCN 35828), setting the following upper limits (AB): Y = 18.3 mag and J = 18.8 mag.


GRB_name: GRB240225B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35830
SUBJECT: GRB 240225B: 3.6m DOT observation
DATE:    24/02/29 06:15:59 GMT
FROM:    Amit Kumar Ror at ARIES <mitturor77894@gmail.com>

Amit K. Ror, Shashi B. Pandey, Rahul Gupta, and Amar Aryan, Shivangi Pandey
(ARIES) report:


We observed the field of GRB 240225B detected by MAXI (Nakajima et al.
2024, GCN 35796), Swift (Evans 2024, GCN 35797), and AstroSat (Joshi et al.
2024, GCN 35798) using the 3.6m Devasthal Optical Telescope of ARIES
Nainital. The observations were started on 2024-02-28 at 01:04:01.085 UT,
i.e., 2.2 days after the MAXI trigger. We have taken multiple frames with a
60-second exposure time in the r, i, and z filters. We detected the OT at
the position of the GOTO afterglow candidate reported by Gompertz et al.
(2024, GCN 35805) in each observed image in the i and z bands and the
stacked image of the r band, indicating a redder nature. The preliminary
magnitude measurements are as follows:


Date Start_UT T_start-T0 (days) Filter  Exp time (s)  Limiting magnitude

=========================================================

2024-02-28 01:04:01.085     2.2     i     60s     19.96 +/- 0.04


Our i-band observation, combined with the observation of Wise et al. (2024,
GCN 35820), yielded a decay index of ~ 0.8 in the i-band.

The magnitude quoted is not corrected for the host and Galactic extinction
in the direction of the burst. Photometric calibration is performed using
the standard stars from the Pan-STARRS catalog.


Our detection is consistent with Gompertz et al. 2024, GCN 35805; Liu et
al. 2024, GCN 35812; Malesani et al. 2024, GCN 35819; Wise et al. 2024, GCN
35820; Gompertz et al. 2024, GCN 35824; Pankov et al. 2024, GCN 35826;
Moskvitin et al. 2024, GCN 35828; and Geoffrey et al. 2024, GCN 35829.


This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is a
recently commissioned facility in the Northern Himalayan region of India
(long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the
Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (
https://www.aries.res.in). Authors of this GCN circular thankfully
acknowledge consistent support from the staff members to run and maintain
the 3.6m DOT.


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35832
SUBJECT: GRB 240225B: VLT/X-shooter redshift
DATE:    24/02/29 10:36:12 GMT
FROM:    Andrea Rossi at INAF <andrea.rossi@inaf.it>

B. Schneider (MIT), G. Pugliese (API), A. Rossi (INAF/OAS), J. Palmerio (GEPI/Obs. de Paris & IAP), D. B. Malesani (DAWN/NBI and Radboud Univ.), Z. Zhu (NAOC), D. Xu (NAOC), B. P. Gompertz (Birmingham), A. Saccardi (GEPI/Obs. de Paris) report on behalf of the Stargate collaboration:

We observed the field of the MAXI/GSC GRB 240225B (Nakajima et al., GCN 35796; see also Joshi et al. 2024, GCN 35798; Kawakubo et al., GCN 35811) using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. Our spectra cover the wavelength range 3000-21000 AA, and consist of 4 exposures of 1200 s each. The observation mid-time is 02:29:56 UT on 2024 Feb 29 (~3.3 days after the MAXI trigger).

In grz images taken with the acquisition camera on Feb 29 01:37:53 UT, we clearly detect the optical afterglow (Gompertz et al., GCN 35805; Liu et al., GCN 35812; Malesani et al., GCN 35819; Wise et al., GCN 35820; Gompertz et al., GCN 35824; Pankov et al., GCN 35826; Moskvitin et al., GCN 35828; Mo et al., GCN 35829; Ror et al., GCN 35830; Sasada et al., GCN 35831), for which we measure a preliminary AB magnitude r ~ 21 (the absolute calibration is uncertain due to the low number of Pan-STARRS calibrators in our small FoV).

In a preliminary reduction of the spectra, we clearly detect a continuum over the entire wavelength range. From detection of multiple absorption features, which we interpret as being due to Fe II, Mg II, AlIII, Ca II, and Fe II*, we infer a common redshift of z = 0.946. We conclude this is the redshift of the burst. We also detect emission lines ([O II] and [O III] doublets, and H_alpha) at a consistent redshift, which we interpret as being due to the GRB host galaxy. As noted by Gompertz & Malesani (GCN 35824), the host galaxy is also detected in the Legacy Survey with r ~ 24.2 and a photometric redshift z ~ 0.9, which is consistent with the value we measured.

We acknowledge expert support from the ESO staff in Paranal, in particular Francesca Lucertini, Israel Blanchard and Thomas Rivinius.


GRB_name: GRB240229A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35833
SUBJECT: GRB 240229A: Fermi GBM Final Real-time Localization
DATE:    24/02/29 14:17:34 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 14:07:07 UT on 29 Feb 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240229A (trigger 730908432.025634 / 240229588).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 199.2, Dec = 16.8 (J2000 degrees, equivalent to J2000 13h 16m, 16d 48'), with a statistical uncertainty of 1.2 degrees.

The angle from the Fermi LAT boresight is 85.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240229588/quicklook/glg_skymap_all_bn240229588.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240229588/quicklook/glg_healpix_all_bn240229588.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240229588/quicklook/glg_lc_medres34_bn240229588.gif


GRB_name: GRB240229A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35834
SUBJECT: GRB 240229A: BALROG localization (Fermi Trigger 730908432 / GRB 240229588)
DATE:    24/02/29 14:44:04 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

B. Biltzinger, T. Preis, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
730908432 at 14:07:07 on 29 Feb. 2024 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position is:
RA(2000.0) = 195.9 deg
Decl.(2000.0) = 16.3 deg
The 1 sigma statistical error radius is 1.7 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB240229588/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB240229588/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB240229588/json

                        


GRB_name: GRB240225B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35835
SUBJECT: Konus-Wind detection of GRB 240225B (long)
DATE:    24/02/29 14:46:36 GMT
FROM:    Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

GRB 240225B (MAXI/GCS detection: Nakajima et al., GCN 35796;
AstroSat CZTI detection: Joshi al., GCN 35798)
triggered Konus-Wind (KW) at T0=72727.251 s UT (20:12:07.251),
i.e., ~3.5 min before the MAXI trigger.

The burst light curve shows a multi-peaked emission
pulse, which starts at ~T0 - 2 s, peaks around ~T0 + 6 s,
and has a total duration of ~35 s.
The emission is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240225_T72727/

As observed by Konus-Wind, the burst had
a fluence of (2.16 Â± 0.35)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 6.144 s,
of (2.87 Â± 0.41)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

A time-averaged spectrum (measured from T0 to T0+41.216 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.37 (-0.14,+0.15),
the high energy photon index beta = -2.74 (-7.26,+0.43),
the peak energy Ep = 270 (-43,+64) keV,
chi2 = 107/97 dof.

A spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.85 (-0.110,+0.10),
the high energy photon index beta = -2.43 (-0.55,+0.24),
the peak energy Ep = 287 (-47,+59) keV,
chi2 = 75/79 dof.

Assuming the redshift z=0.946 (Schneider et al., GCN 35832)
and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,
and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the burst isotropic energy release E_iso to (5.38 Â± 0.95)x10^52 erg,
the isotropic peak luminosity L_iso to (1.87 Â± 0.27)x10^52 erg/s,
the rest-frame peak energy of the time-integrated spectrum Ep,i,z to ~525 keV,
and the rest-frame peak energy at the peak of the emission Ep,p,z to ~558 keV.
With the obtained estimates, GRB 240225B is inside 68% prediction bands for
both 'Amati' and 'Yonetoku' relations derived for the sample of >300 long
KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021),
see http://www.ioffe.ru/LEA/GRBs/GRB240225_T72727/GRB240225B_rest_frame.pdf

All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.


GRB_name: GRB240225B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35836
SUBJECT: GRB 240225B: Swift ToO observations
DATE:    24/02/29 15:26:30 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the MAXI GRB 240225B. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021682

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the MAXI event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB240229A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35838
SUBJECT: Fermi GRB 240229A: Global MASTER-Net observations report
DATE:    24/02/29 18:31:22 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 240229A ( Fermi GBM team, GCN 35833) errorbox  565 sec after notice time and 608 sec after trigger time at 2024-02-29 14:17:15 UT, with upper limit up to  17.3 mag. The observations began at zenith distance = 57 deg. The sun  altitude  is -44.1 deg. 

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 240229A errorbox  12048 sec after notice time and 12090 sec after trigger time at 2024-02-29 17:28:37 UT, with upper limit up to  17.4 mag. The observations began at zenith distance = 80 deg. The sun  altitude  is -28.0 deg. 

The galactic latitude b = 78 deg., longitude l = 336 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2388695

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     668 | 2024-02-29 14:17:15 |         MASTER-Amur | (13h 15m 43.59s , +16d 45m 26.5s) |   C |   120 | 16.8 |        
     823 | 2024-02-29 14:19:34 |         MASTER-Amur | (13h 15m 45.52s , +16d 46m 56.6s) |   C |   150 | 17.1 |        
    1008 | 2024-02-29 14:22:24 |         MASTER-Amur | (13h 15m 40.46s , +16d 45m 49.5s) |   C |   180 | 17.1 |        
    1207 | 2024-02-29 14:25:44 |         MASTER-Amur | (13h 15m 39.17s , +16d 46m 37.0s) |   C |   180 | 17.1 |        
    1407 | 2024-02-29 14:29:03 |         MASTER-Amur | (13h 15m 45.28s , +16d 45m 24.1s) |   C |   180 | 17.1 |        
    1606 | 2024-02-29 14:32:22 |         MASTER-Amur | (13h 15m 39.10s , +16d 44m 09.9s) |   C |   180 | 17.0 |        
    2526 | 2024-02-29 14:48:42 |         MASTER-Amur | (13h 18m 12.51s , +18d 16m 37.4s) |   C |    60 | 16.4 |        
    2605 | 2024-02-29 14:50:02 |         MASTER-Amur | (13h 26m 32.91s , +18d 16m 02.2s) |   C |    60 | 16.6 |        
    2779 | 2024-02-29 14:52:55 |         MASTER-Amur | (13h 10m 35.17s , +18d 15m 01.2s) |   C |    60 | 16.6 |        
    3726 | 2024-02-29 15:08:42 |         MASTER-Amur | (13h 18m 05.95s , +18d 14m 13.0s) |   C |    60 | 16.9 |        
    3806 | 2024-02-29 15:10:02 |         MASTER-Amur | (13h 26m 39.19s , +18d 14m 47.0s) |   C |    60 | 17.2 |        
    3972 | 2024-02-29 15:12:49 |         MASTER-Amur | (13h 10m 34.58s , +18d 13m 28.9s) |   C |    60 | 17.3 |        
    4802 | 2024-02-29 15:26:39 |         MASTER-Amur | (13h 18m 12.01s , +18d 14m 50.4s) |   C |    60 | 17.1 |        
    4882 | 2024-02-29 15:27:59 |         MASTER-Amur | (13h 26m 31.08s , +18d 14m 32.1s) |   C |    60 | 17.1 |        
    5041 | 2024-02-29 15:30:38 |         MASTER-Amur | (13h 10m 36.75s , +18d 13m 13.8s) |   C |    60 | 17.2 |        
    7843 | 2024-02-29 16:17:19 |         MASTER-Amur | (13h 10m 09.39s , +16d 15m 21.3s) |   C |    60 | 16.6 |        
    8555 | 2024-02-29 16:29:11 |         MASTER-Amur | (13h 18m 24.16s , +16d 15m 56.3s) |   C |    60 | 16.4 |        
    8861 | 2024-02-29 16:34:17 |         MASTER-Amur | (13h 10m 09.58s , +16d 15m 00.1s) |   C |    60 | 16.5 |        
    9561 | 2024-02-29 16:45:58 |         MASTER-Amur | (13h 18m 31.22s , +16d 15m 28.9s) |   C |    60 | 16.5 |        
    9802 | 2024-02-29 16:49:58 |         MASTER-Amur | (13h 10m 05.38s , +16d 12m 45.1s) |   C |    60 | 16.5 |        
   10645 | 2024-02-29 17:04:01 |         MASTER-Amur | (13h 18m 25.32s , +16d 12m 21.5s) |   C |    60 | 16.4 |        
   12121 | 2024-02-29 17:28:37 |   MASTER-Kislovodsk | (13h 07m 59.15s , +18d 23m 53.3s) |   C |    60 | 17.2 |        
   12915 | 2024-02-29 17:41:52 |   MASTER-Kislovodsk | (13h 07m 19.51s , +16d 29m 19.2s) |   C |    60 | 17.2 |        
   12995 | 2024-02-29 17:43:12 |   MASTER-Kislovodsk | (13h 15m 39.59s , +16d 30m 02.2s) |   C |    60 | 16.9 |        
   13154 | 2024-02-29 17:45:51 |   MASTER-Kislovodsk | (13h 07m 59.06s , +18d 22m 14.0s) |   C |    60 | 17.4 |        
   13551 | 2024-02-29 17:52:28 |   MASTER-Kislovodsk | (13h 15m 32.94s , +18d 24m 05.9s) |   C |    60 | 16.9 |        
   13710 | 2024-02-29 17:55:07 |   MASTER-Kislovodsk | (13h 23m 59.86s , +18d 21m 58.6s) |   C |    60 | 17.1 |        
   14809 | 2024-02-29 18:12:26 |         MASTER-Amur | (13h 22m 10.81s , +14d 44m 23.7s) |   R |   180 | 15.4 |        
   15019 | 2024-02-29 18:15:56 |         MASTER-Amur | (13h 20m 47.98s , +15d 00m 15.9s) |   R |   180 | 15.0 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240225B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35839
SUBJECT: GRB 240225B: further SAO RAS optical observations
DATE:    24/02/29 18:48:28 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin, O. I. Spiridonova (SAO RAS)
report on behalf of the GRB follow-up team.

We observed the field of GRB 240225B (Nakajima et al., GCN 35796;
Evans, GCN 35797; Joshi et al., GCN 35798; D'Ai et al., GCN 35810;
Kawakubo et al., GCN 35811; Frederiks et al., GCN 35835)
with the SAO RAS 1m telescope Zeiss-1000 equipped with CCD-photometer.
We obtained 8 x 300 sec frames in the Rc band on Feb. 29,
17:11:52--18:03:46 UT (t_mid - T0 = 3.8903 days).


The OT (Gompertz et al., GCN 35805; Liu et al., GCN 35812;
Malesani et al., GCN 35819; Wise et al., GCN 35820;
Gompertz & Malesani, GCN 35824; Pankov et al., GCN 35826;
Ror et al., GCN 35830; Sasada et al., GCN 35831; Schneider et al.,
GCN 35832) is clearly detected in our stacked frame
with the brightness of R = 21.11 +/- 0.04.

The photometry is based on nearby SDSS stars (magnitudes converted
with Lupton 2005 equations).


GRB_name: GRB240229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35842
SUBJECT: GRB 240229A: CALET Gamma-Ray Burst Monitor detection
DATE:    24/03/01 04:42:26 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii,
Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 240229 (Fermi GBM Final Real-time Localization: 
Fermi GBM team, GCN Circ. 35833; BALROG localization: Biltzinger et al.,
GCN Circ 35834; INTEGRAL SPI ACS: Trigger Num. 10602)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 
14:07:07.40 UTC on 29 February 2024
(http://cgbm.calet.jp/cgbm_trigger/flight/1393250567/).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a double-peaked structure that starts
at T+2.9 sec, peaks at T+26.5 sec, and ends at T+36.8 sec.
The T90 and T50 durations measured by the SGM data are 27.6 +/- 2.5 sec
and 19.2 +/- 0.4 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1393250567/index.html

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB240229A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35844
SUBJECT: GRB 240229A: DDOTI Upper Limits on the Afterglow
DATE:    24/03/02 00:54:46 GMT
FROM:    Kin O. C. L. Mendoza at Instituto de Astronoma, UNAM <koclopez@astro.unam.mx>

OcÃ©lotl Lopez (UNAM), Alan M. Watson (UNAM), Rosa L. Becerra (Tor
Vergata Roma),
Margarita Pereyra (UNAM), Nat Butler (ASU), Simone Dichiara (Penn state

university), William H. Lee (UNAM), Alexander Kutyrev (GSFC/UMD),
Tsvetelina Dimitrova (ASU) and Eleonora Troja (Tor Vergata Roma) report:


We observed the field of the Fermi GBM GRB 240229A (Fermi GBM team 2024,
GCN Circ. 35833) with the DDOTI wide-field imager at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir (
http://ddoti.astroscu.unam.mx) from 2024-03-01  06:10:00 to 12:58:45 UTC
(16.05 to 22.86 hours after the trigger).

We observed a region of 7 degrees in RA by 7 degrees in declination
centered on the Fermi GBM Final Position of RA = 199.18 and Dec = 16.77
(J2000 degrees). This region contains 1 instrumental field or about 49
square degrees. We obtained 103 minutes of exposure per instrumental field
in the w filter. We obtained AB photometry by calibration against the APASS
catalog.

We detect no likely candidates for the afterglow to our 10-sigma upper
limits of w = 19.90 - 20.64 (inter-quartile).

We thank the staff of the Observatorio AstronÃ³mico Nacional on San Pedro

MÃ¡rtir.


GRB_name: GRB240225C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35846
SUBJECT: GRB 240225C: Glowbug gamma-ray detection
DATE:    24/03/02 14:35:03 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240225C, which was also detected by AstroSat/CZTI (GCN 35799), GRBAlpha (GCN 35802), CALET (GCN 35806), INTEGRAL/SPI-ACS (Trigger 10590), and Konus/Wind (Trig_Time 05:19:33.355).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-02-25 05:19:33.944 with a duration of 13.8 s and a total significance of about 83 sigma.  The light curve comprises a single peak.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=1.5 and a cutoff energy ("Epeak") of 270 keV.  The modeled 10-10000 keV fluence is 6.4e-06 erg/cm^2.
 
The best-fit localization is RA, Decl. (J2000, deg) = 351.0, 25.7 with a radius of 4.2 deg (95% confidence), with a highly uncertain systematic uncertainty.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240225B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35848
SUBJECT: GRB 240225B: Glowbug gamma-ray detection
DATE:    24/03/03 04:22:32 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240225B, which was also detected by MAXI/GSC (GCN 35796), AstroSat/CZTI (GCN 35798), CALET (GCN 35811), and Konus/Wind (GCN 35835).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-02-25 20:11:58.416 with a duration of 38.9 s and a total significance of ~89 sigma.  The light curve comprises a multi-peaked structure with two primary peaks at ~T0+3s and ~T0+8s, and a fainter peak at ~T0+34s.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission in two defined intervals from T0 to T0+22.5s and T0+22.5s to +38.9s resulted respectively in photon indices dN/dE~E^x of x=0.6 and x=0.7, and cutoff energies ("Epeak") of 324 keV and 262 keV.  The respective modeled 10-10000 keV fluences are 9.7e-06 erg/cm^2 and 2.0e-06 erg/cm^2.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240303A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35849
SUBJECT: GRB 240303A: Swift detection of a burst
DATE:    24/03/03 07:00:31 GMT
FROM:    Amy <yarleen@gmail.com>


A. Y. Lien (U Tampa), V. D'Elia (SSDC & INAF-OAR),
A. Melandri (INAF-OAR), K. L. Page (U Leicester) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 06:33:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240303A (trigger=1218452).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 229.748, -57.375 which is 
   RA(J2000) = 15h 19m 00s
   Dec(J2000) = -57d 22' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual with an image trigger, the
BAT light curve does not show any significant structure. 

The XRT began observing the field at 06:35:35.6 UT, 136.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 229.7375, -57.3633 which is equivalent to:
   RA(J2000)  = 15h 18m 57.00s
   Dec(J2000) = -57d 21' 47.9"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 46 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
143 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. 

The source location is on the Galactic plane (Glon=321.816 deg, Glat=-0.003 deg). 
At this moment we are unable to tell if this is a GRB or a galactic transient,
which we would name Swift J151857.0-572147. We await further ground data to
determine the nature of the source. 

Burst Advocate for this burst is A. Y. Lien (yarleen AT gmail.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB240303B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35851
SUBJECT: GRB 240303B: BALROG localization (Fermi Trigger 731161136 / GRB 240303513)
DATE:    24/03/03 13:52:09 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
731161136 at 12:18:51 on 03 March 2024 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position is:
RA(2000.0) = 308.5 deg
Decl.(2000.0) = 1.5 deg
The 1 sigma statistical error radius is 4.5 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB240303513/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB240303513/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB240303513/json

                        


GRB_name: GRB240215A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35852
SUBJECT: GRB 240215A: Swift-XRT afterglow detection
DATE:    24/03/03 16:24:26 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), C. Salvaggio (INAF-OAB), M.
Ferro (INAF-OAB), R. Brivio (INAF-OAB), J. D. Gropp (PSU), S. Dichiara
(PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT
team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 240215A in a series of observations tiled
on the sky. The total exposure time is 4.4 ks, distributed over 4
tiles; the maximum exposure at a single sky location was 2.7 ks. The
data were collected between T0+44.5 ks and T0+1384.7 ks, and are
entirely in Photon Counting (PC) mode. 

Four uncatalogued X-ray sources are detected, of which one ("Source 2")
is fading with >3-sigma significance, and is therefore likely the GRB
afterglow.  The position of this source is RA, Dec=132.0101, -6.5099
which is equivalent to:

RA (J2000): 08:48:2.42
Dec(J2000): -06:30:35.5

with an uncertainty of 8.1 arcsec (radius, 90% confidence).  This
position is 14.9 arcmin from the Swift/BAT position.  The source is
fading with alpha >0.5.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021670.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00123.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB240303A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35853
SUBJECT: Swift J151857.0-572147: Confirmation of a new galactic transient
DATE:    24/03/03 16:29:37 GMT
FROM:    Jamie Kennea at Penn State <jak51@psu.edu>

J. A. Kennea (PSU), A. Y. Lien (U Tampa) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team:

Swift Trigger #1218452 (GCN #35849), previously named GRB 240303A but considered likely to be a galactic transient named Swift J151857.0-572147, has been confirmed to be a transient. Repeated observations of the source show it to be consistently bright, with no signs of fading. This combined with its localization within the Galactic Plane, and the fact that this was a BAT Image trigger, confirms its nature as a Galactic Transient.

A spectral fit to the combined Swift/XRT data show an absorption N_H = 5.6 +/- 0.06 x 10^22 cm^-2 and a power-law slope with photon index of 1.78 +/- 0.02. The average flux, corrected for absorption is 1.40 +/- 0.02 x 10^-8 erg/s/cm^2 (0.5-10 keV).

We encourage follow-up observations in order to determine the nature of this new transient.


GRB_name: GRB240303A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35854
SUBJECT: Swift GRB 240303A: Global MASTER-Net observations report
DATE:    24/03/03 18:08:32 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 240303A ( A. Y. Lien et al., GCN 35849) errorbox  40932 sec after notice time and 41012 sec after trigger time at 2024-03-03 17:56:51 UT, with upper limit up to  15.7 mag. Observations started at twilight.  The observations began at zenith distance = 84 deg. The sun  altitude  is -10.4 deg. 

The galactic latitude b = -0 deg., longitude l = 322 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2390165

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   41102 |         MASTER-SAAO |   C |   180 | 15.7 |        
   41102 |         MASTER-SAAO |   C |   180 | 15.2 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240303C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35855
SUBJECT: GRB 240303C: BALROG localization (Fermi Trigger 731189113 / GRB 240303837)
DATE:    24/03/03 20:55:32 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
731189113 at 20:05:08 on 03 March 2024 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position is:
RA(2000.0) = 324.2 deg
Decl.(2000.0) = -49.0 deg
The 1 sigma statistical error radius is 3.0 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB240303837/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB240303837/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB240303837/json

                        


GRB_name: GRB240303B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35857
SUBJECT: GRB 240303B: CALET Gamma-Ray Burst Monitor detection
DATE:    24/03/04 02:54:38 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

S. Nakahira (JAXA), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), Y. Asaoka (ICRR), S. Torii,
Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 240303B (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 35850; BALROG localization: Preis et al., GCN Circ 35851; 
INTEGRAL SPI-ACS: Trigger 10612; GECAM: Trigger 301) triggered the 
CALET Gamma-ray Burst Monitor (CGBM) at 12:18:48.35 UTC on 3 March 2024
(http://cgbm.calet.jp/cgbm_trigger/flight/1393503263/).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure that starts
at T+2.7 sec, peaks at T+7.2 sec, and ends at T+11.2 sec.
The T90 and T50 durations measured by the SGM data are 5.5 +/- 0.4 sec
and 2.0 +/- 0.1 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1393503263/index.html

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB240303A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35858
SUBJECT: Swift detection of Swift J151857.0-572147
DATE:    24/03/04 09:14:44 GMT
FROM:    P.A. Evans at U. Leicester <pae9@leicester.ac.uk>


E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR),
P. A. Evans (U Leicester), J. A. Kennea (PSU), A. Melandri (INAF-OAR),
K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 08:53:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located Swift J151857.0-572147 (trigger=1218604).  Swift slewed
immediately to the object. The BAT on-board calculated location is 
RA, Dec 229.732, -57.354 which is 
   RA(J2000) = 15h 18m 56s
   Dec(J2000) = -57d 21' 15"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty). As is usual with an image trigger, the
BAT light curve does not show any significant structure. 

The XRT began observing the field at 08:56:20.6 UT, 189.7 seconds after
the BAT trigger. XRT found a bright X-ray source located at RA, Dec
= 229.7358, -57.3617 which is equivalent to:
   RA(J2000)  = 15h 18m 56.59s
   Dec(J2000) = -57d 21' 42.1"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 28 arcseconds from the BAT onboard position, within the BAT
error circle, and consistent with the localisation of Swift J151857.0-572147
reported in GCN Circs. 35849 & 35853. 

UVOT took a finding chart exposure of 250 seconds with the U filter
starting 195 seconds after the BAT trigger. No credible afterglow
candidate has been found in the initial data products. 

This object is the same as BAT trigger 1218452, which was originally
identified as GRB 240303A (Lien et al., GCN Circ. 35849) but later confirmed
as a Galactic transient Swift J151857.0-572147 (Kennea et al., GCN Circ. 35853). 


GRB_name: GRB240303B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35860
SUBJECT: GRB 240303B: Fermi GBM Detection
DATE:    24/03/04 15:41:29 GMT
FROM:    rachel.hamburg@ijclab.in2p3.fr

R. Hamburg (CNRS/IN2P3/IJCLab) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 12:18:51.24 UT on 03 March 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240303B (trigger 731161136 / 240303513).
The on-ground calculated location is reported in GCN 35850.
This burst was also detected by CALET (Nakahira et al., 2024; GCN 35857)
and the INTEGRAL SPI-ACS (trigger 10612).

The angle from the Fermi LAT boresight is 96 degrees.

The GBM light curve consists of a single bright pulse with a duration (T90)
of about 5.9 s (50-300 keV). The time-averaged spectrum
from T0-1.0 to T0+8.2 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.33 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 540 +/- 20 keV.
A Band function fits the spectrum equally well
with Epeak= 510 +/- 20 keV, alpha = -0.30 +/- 0.04 and beta = -3 +/- 0.3.

The event fluence (10-1000 keV) in this time interval is
(2.31 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.9 s in the 10-1000 keV band is 18.5 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB240303B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35862
SUBJECT: IPN triangulation of GRB 240303B
DATE:    24/03/04 18:38:51 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The long-duration GRB 240303B
(Fermi-GBM detection: The Fermi GBM team, GCN 35850;
Hamburg and Meegan, GCN 35860;
BALROG localization: Preiset al., GCN 35851;
CALET-GBM detection: Nakahira et al., GCN 35857)
has been detected by Fermi (GBM trigger 731161136),
INTEGRAL (SPI-ACS), Konus-Wind, CALET (GBM),
and Mars-Odyssey (HEND), so far, at about 44331 s UT (12:18:51).

We have triangulated this GRB to the following annuli:
---------------------------------------------------
annulus           R.A.     Dec.     R     dR (3sigma)
                 (deg)    (deg)   (deg)     (deg)
---------------------------------------------------
Konus-GBM       320.846  -16.019  24.529  2.743
GBM-SPI-ACS     194.036   78.908  88.157  8.554
GBM-HEND        317.319  -17.507  23.796  0.133
---------------------------------------------------
The annuli intersect to form a long 8.1 sq.deg (3 sigma)
localization region.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final and the BALROG localizations.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240303_T44327/IPN

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN circular.


GRB_name: GRB240303B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35864
SUBJECT: Konus-Wind detection of GRB 240303B
DATE:    24/03/04 18:41:13 GMT
FROM:    Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 240303B (Fermi GBM detection:
Fermi GBM team, GCN 35850; Hamburg and Meegan, GCN 35860;
CALET detection: Nakahira et al., GCN 35857;
IPN localization: Kozyrev et al., GCN 35862)
triggered Konus-Wind (KW) at T0=44327.406 s UT (12:18:47.406).

The burst light curve shows a bright initial pulse,
which starts at ~T0-0.5s, peaks at ~T0+4s, and has a duration of ~6.5s.
This pulse is followed by a weaker extended emission that lasts
up to ~T0+250s.
The emission in is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240303_T44327/

As observed by Konus-Wind, the initial pulse had
a fluence of (2.62 Â± 0.27)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0+4.032 s,
of (1.11 Â± 0.12)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

A time-averaged spectrum of this pulse (measured from T0 to T0+6.4 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.21 (-0.12,+0.12),
the high energy photon index beta = -2.69 (-0.77,+0.27),
the peak energy Ep = 422 (-49,+61) keV,
chi2 = 92/77 dof.

A spectrum of the extended emission (measured from T0+30.976 to T0+252.16 s)
is best fit by a simple power-law (PL) function with
the PL index of -1.42(-0.22,+0.18), chi2 = 86/99 dof.
A 20-3000 keV fluence in this interval is estimated to (2.42 Â± 0.63)x10^-5 erg/cm^2.


All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB240218A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35866
SUBJECT: GRB240218A: ATCA observation of the radio counterpart
DATE:    24/03/04 19:10:37 GMT
FROM:    Aishwarya L Thakur at INAF-IAPS, Rome <aishth@outlook.com>

A.L. Thakur (INAF-IAPS), R. Ricci (INAF-IRA), G. Bruni, L. Piro, G. Gianfagna (INAF-IAPS), M. Wieringa (ATNF) report:

We observed the high-redshift GRB240218A (Page et al. GCN 35742, Veres and Meegan et al. GCN 35755, Svinkin et al. GCN 37558, Dâ€™Avanzo et al. GCN 35747, Saccardi et al. GCN 35756) with the Australian Telescope Compact Array under program C3546 (PI Thakur) on 4 March 2024 at a mean epoch of ~ 15 days post-burst. Observations were performed in the C-band for a total duration of ~6 hours.

Given the declination of the radio counterpart, the ATCA beam in the current array configuration is highly elongated on the North-South axis. We performed a check for potential confusing sources using a VLASS field at 3 GHz, centred on the position of the radio afterglow as detected by the VLA at RA=10:47:11.480 Dec=+01:16:35.29 (Schroeder et al., GCN 35794). No confusing sources are visible down to an rms of 130 uJy/beam.

In the preliminary 5.5 GHz ATCA image, we detect a source with a flux of ~ 0.2 mJy at a position consistent with the VLA detection.

Further monitoring of this counterpart is planned.

We thank CSIRO Space and Astronomy staff, particularly Jamie Stevens, for excellent support in planning and performing these observations. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42), which is funded by the Australian Government for operation as a National Facility managed by CSIRO.


GRB_name: GRB240305A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35869
SUBJECT: GRB 240305A: Fermi GBM Final Real-time Localization
DATE:    24/03/05 09:59:51 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 09:49:21 UT on 5 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240305A (trigger 731324966.26389 / 240305409).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 21.1, Dec = -42.1 (J2000 degrees, equivalent to J2000 01h 24m, -42d 06'), with a statistical uncertainty of 9.8 degrees.

The angle from the Fermi LAT boresight is 67.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305409/quicklook/glg_skymap_all_bn240305409.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305409/quicklook/glg_healpix_all_bn240305409.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305409/quicklook/glg_lc_medres34_bn240305409.gif


GRB_name: GRB240227A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35871
SUBJECT: Improved IPN triangulation of GRB 240227A (short)
DATE:    24/03/05 14:16:50 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the MGNS/BepiColombo team,

J. Benkhoff on behalf of the BepiColombo team,

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

and

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:

Using the BepiColombo (MGNS) data we have improved
the previous IPN error box (Svinkin et al., GCN 35821).

The coordinates of the updated 3 sigma error box are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
   18.725 (01h 14m 54s) -34.410 (-34d 24' 34")
 Corners:
   18.512 (01h 14m 03s) -35.909 (-35d 54' 32")
   18.933 (01h 15m 44s) -33.175 (-33d 10' 30")
   18.900 (01h 15m 36s) -32.912 (-32d 54' 42")
   18.488 (01h 13m 57s) -35.644 (-35d 38' 37")
 ---------------------------------------------
The error box area is 561 sq. arcmin, and its maximum
dimension is 3.01 deg (the minimum one is 3.4 arcmin).
The Sun distance was 44 deg.

This box may be further improved.

Updated triangulation map and HEALPix FITS files are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240227_T16812/IPN/


GRB_name: GRB240229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35872
SUBJECT: GRB 240229A: VZLUSAT-2 detection
DATE:    24/03/05 15:04:12 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),  N. Werner  (Masaryk U.), M. Ohno (Hiroshima U.),  L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU)  -- the VZLUSAT-2/GRB payload collaboration.

The long-duration GRB 240229A (Fermi/GBM detection: GCN 35833; CALET/CGBM detection: GCN 35842; INTEGRAL/SPI-ACS peak detection at 2024-02-29 ~14:07:35 UT) was detected by the GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).

The data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2024-02-29 14:07:19 (14:06:59) UTC. The T90 duration is 27 s (27 s) and the significance during T90 reaches 16 sigma (11 sigma) for detector unit no. 0 (no. 1).

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB240229A_GCN_VZLUSAT2.pdf

We note that the light curve measured by VZLUSAT-2 is shifted by approximately 14 s with respect to light curves obtained by other missions. At the moment, the cause of this discrepancy is being investigated.

All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.


GRB_name: GRB240303B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35873
SUBJECT: GRB 240303B: VZLUSAT-2 detection
DATE:    24/03/05 15:05:01 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),  N. Werner  (Masaryk U.), M. Ohno (Hiroshima U.),  L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU)  -- the VZLUSAT-2/GRB payload collaboration.

The long-duration GRB 240303B (Fermi/GBM detection: GCN 35850; CALET/CGBM detection: GCN 35857; Konus/Wind detection: GCN 35864; INTEGRAL/SPI-ACS peak detection at 2024-03-03 ~12:18:56 UT) was detected by the GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).

The data acquisition was performed by the GRB detector unit no. 1. The detection was confirmed at the peak time 2024-03-03 12:18:38 UTC. The T90 duration is 6 s and the significance during T90 reaches 27 sigma.

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB240303B_GCN_VZLUSAT2.pdf

We note that the light curve measured by VZLUSAT-2 is shifted by approximately 17 s with respect to light curves obtained by other missions. At the moment, the cause of this discrepancy is being investigated.

All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.


GRB_name: GRB240227A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35874
SUBJECT: Konus-Wind detection of GRB 240227A (short/hard)
DATE:    24/03/05 16:30:28 GMT
FROM:    Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The short GRB 240227A (Fermi-GBM detection: The Fermi GBM team, GCN 35814;
IPN triangulation: Svinkin et al., GCN 35821; Kozyrev et al., GCN 35871).
triggered Konus-Wind (KW) at T0=16812.986 s UT (04:40:12.986).

The burst light curve shows a single multi-peaked emission pulse
which starts at ~T0-0.400 s and has a duration of ~0.5 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240227_T16812/

As observed by Konus-Wind, the burst had
the total fluence of 1.72(-0.28,+0.36)x10^-6 erg/cm^2
and a 16-ms peak energy flux, measured from T0+0.032 s,
of 8.21(-2.63,+3.09)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

Since a major part of the burst emission was detected before the trigger,
a time-averaged spectral analysis was performed using the KW 3-channel light curve data.
Modeling the 3-channel time-integrated spectrum (measured from T0-0.400 s to T0+0.096 s)
by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.47 (-0.24, + 0.28) and Ep = 688(-133,+222) keV.

A multi-channel spectrum near the peak count rate (measured from T0 to T0+0.064 s)
is best fit in the 20 keV - 15 MeV range by a CPL model
with  alpha = -0.12(-0.47,+0.70) and Ep = 759(-233,+403) keV (chi2 = 6.4/10 dof).


All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.


GRB_name: GRB240305B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35876
SUBJECT: GRB 240305B: Fermi GBM Final Localization
DATE:    24/03/05 20:11:14 GMT
FROM:    Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 03:52:49.30 UT on 05 March 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240305B (trigger 731303574 / 240305162).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 10.37, Dec = -21.98 (J2000 degrees, equivalent to J2000 00h 41m, -21d 59'),
with a statistical uncertainty of 3.05 degrees.

The angle from the Fermi LAT boresight is 35 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305162/quicklook/glg_skymap_all_bn240305162.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305162/quicklook/glg_healpix_all_bn240305162.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305162/quicklook/glg_lc_medres34_bn240305162.gif"


GRB_name: GRB240218A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35877
SUBJECT: GRB 240218A: Chandra Detection and Jet Break Confirmation
DATE:    24/03/05 21:39:51 GMT
FROM:    corinna.pena@utah.edu

C. PeÃ±a, T. Laskar (Utah), G. Schroeder (Northwestern), and K. D. Alexander (Arizona) report:

We observed GRB 240218A (Page et al., GCN 35742; Veres et al., GCN 35755; Svinkin et al., GCN 35758) with Chandra/ACIS-S beginning on 2024 Mar 4 at 23:02:14 UT (16 days post-burst) for a total exposure of 20ks. In preliminary analysis, we detect a point source with a count rate of 5.5e-4 counts/s (0.3-8 keV; observer frame) at a position consistent with the VLA and XRT position (Schroeder et al., GCN 35794; Evans et al. GCN 35748). Using spectral parameters from the Swift/XRT PC-mode spectrum at a redshift z=6.782 (Saccardi et al., GCN 35756), we find a preliminary unabsorbed flux of ~ 1.2e-14 erg/(s cm^2) in the 0.3-8 keV band (observer frame).

This measurement confirms a potential break in the Swift/XRT observations at ~ 0.8 days after the trigger. The post-break decay rate of ~ -1.9 is consistent with a jet break. Further analysis is underway.

We thank Pat Slane, Douglas Swartz, and James Steiner for approving our DDT request. We thank Jen Lauer along with the rest of the CXC staff for arranging and executing the observations.


GRB_name: GRB240218A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35878
SUBJECT: GRB 240218A: ALMA detection
DATE:    24/03/05 21:41:49 GMT
FROM:    Tanmoy Laskar at U of Bath <tanmoylaskar@gmail.com>

T. Laskar, C. PeÃ±a (Utah), G. Schroeder (Northwestern), and K. D. Alexander
(Arizona) report on behalf of a larger collaboration:

"We observed GRB 240218A (Page et al., GCN 35742; Veres et al., GCN 35755;
Svinkin et al., GCN 35758) with the Atacama Large Millimeter/Submillimeter
Array (ALMA) at 97.5 GHz beginning on 2024 March 02 02:46:33 UT (13.0 d
after the burst). ALMA observations of this burst were delayed due to
ALMA's annual February shutdown.

Preliminary analysis reveals a mm source with flux density of ~ 0.1 mJy at
97.5 GHz and position:

RA (J2000) = 10:47:11.5
Dec (J2000) = 1:16:36.0

with uncertainty ~ 0.3" in each coordinate, consistent with the X-ray
position (Evans et al. GCN 35748) and radio position (Schroeder et al., GCN
35794).

We thank the JAO staff, AoD, P2G, and the entire ALMA team for their help
with these observations."


GRB_name: GRB231028C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35879
SUBJECT: GRB 231028C: Glowbug gamma-ray confirmation of a prior burst
DATE:    24/03/05 21:53:20 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, M. Kerr, J.E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 231028C, which was also detected by Konus/Wind (Trigger time 12:31:37.779 UT).  This was previously identified in Glowbug data as a candidate GRB, and we report it here as confirmation of the independent Konus/Wind trigger.
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-10-28 12:31:37.104 with a duration of 4.1 s and a total significance of about 12.7 sigma.  The light curve comprises a single peak.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=0.6 and a cutoff energy ("Epeak") of 303 keV.  The modeled 10-10000 keV fluence is 2.1e-06 erg/cm^2.
 
The best-fit localization was RA, Decl. (J2000, deg) = 125.5,-45.5 with a radius of 22.3 deg (95% confidence), with a highly uncertain systematic uncertainty.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240305A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35880
SUBJECT: GRB 240305A: Swift/BAT-GUANO arcminute localization of a burst
DATE:    24/03/05 21:56:16 GMT
FROM:    Jimmy DeLaunay at Penn State <delauj2@gmail.com>

James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC)  report:

Swift/BAT did not localize GRB 240305A onboard (T0: 2024-03-05T09:49:21.26 UTC, Fermi/GBM trigger 731324994).

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

In ground analysis of the available TTE data, we find the position of
the burst with SNR 9.7 in the image domain using a slew mosaic technique.

The BAT position is
RA, Dec = 6.278, -43.904, which is:
    RA (J2000)     00h 25m 06.72s
    Dec (J2000)  -43d 54' 14.4"
with an estimated uncertainty of 5 arcminutes

XRT and UVOT will not follow-up due to sun constraints.
Results of follow-up observations will be reported in future circulars.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB240305C
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35881
SUBJECT: GRB 240305C: Fermi GBM Final Real-time Localization
DATE:    24/03/05 22:27:23 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 22:16:36 UT on 5 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240305C (trigger 731369801.549802 / 240305928).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 261.1, Dec = -3.2 (J2000 degrees, equivalent to J2000 17h 24m, -3d 12'), with a statistical uncertainty of 9.1 degrees.

The angle from the Fermi LAT boresight is 74.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305928/quicklook/glg_skymap_all_bn240305928.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305928/quicklook/glg_healpix_all_bn240305928.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240305928/quicklook/glg_lc_medres34_bn240305928.gif


GRB_name: GRB240305C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35882
SUBJECT: Fermi GRB 240305C: Global MASTER-Net observations report
DATE:    24/03/05 22:30:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 240305C ( Fermi GBM team, GCN 35881) errorbox  390 sec after notice time and 423 sec after trigger time at 2024-03-05 22:23:40 UT, with upper limit up to  13.6 mag. The observations began at zenith distance = 77 deg. The sun  altitude  is -50.3 deg. 

The galactic latitude b = 17 deg., longitude l = 20 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2392695

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     454 | 2024-03-05 22:23:40 |   MASTER-Kislovodsk | (17h 01m 25.66s , +00d 55m 11.6s) |   C |    60 | 13.6 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240306A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35885
SUBJECT: GRB 240306A: Fermi GBM Final Real-time Localization
DATE:    24/03/06 06:56:45 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 06:45:50 UT on 6 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240306A (trigger 731400355.209016 / 240306282).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 20.6, Dec = -42.0 (J2000 degrees, equivalent to J2000 01h 22m, -42d 00'), with a statistical uncertainty of 3.9 degrees.

The angle from the Fermi LAT boresight is 87.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240306282/quicklook/glg_skymap_all_bn240306282.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240306282/quicklook/glg_healpix_all_bn240306282.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240306282/quicklook/glg_lc_medres34_bn240306282.gif


GRB_name: GRB240305C
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35886
SUBJECT: GRB 240305C: AstroSat CZTI detection of a short burst
DATE:    24/03/06 08:35:52 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a short-duration GRB 240305C which was also detected by Fermi-GBM (Fermi GBM team, GCN Circ. 35881).

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-03-05 22:16:36.87 UTC. The measured peak count rate associated with the burst is 606 (+300, -112) counts/s above the background in the combined data of three quadrants (out of four), with a total of 104 (+31, -29) counts. The local mean background count rate was 258 (+9, -16) counts/s. Using cumulative rates, we measure a T90 of 0.45 (+0.04, -0.12) s.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240305A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35888
SUBJECT: GRB 240305A: Fermi GBM observation
DATE:    24/03/06 15:13:50 GMT
FROM:    Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 09:49:21.26 UT on 05 March 2024, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 240305A (trigger 731324966 / 240305409),
which was also detected by the Swift/BAT GUANO (DeLaunay et al. 2024, GCN 35880).
The Fermi GBM Final Real-time Localization (GCN 35869)
is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 56 degrees.

The GBM light curve consists of a single weak emission episode
with a duration (T90) of about 13 s (50-300 keV).
The time-averaged spectrum from T0-2.3 s to T0+10.2 s is
best fit by a simple power law function with index -2.06 +/- 0.07.

The event fluence (10-1000 keV) in this time interval is
(1.29 +/- 0.12)e-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.0 s in the 10-1000 keV band
is 2.05 +/- 0.19 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB240306A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35889
SUBJECT: GRB 240306A: Swift/BAT-GUANO detection of a burst
DATE:    24/03/06 17:04:09 GMT
FROM:    Tyler Parsotan  at NASA GSFC <tyler.parsotan@nasa.gov>

Tyler Parsotan (NASA GSFC), James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU) report:

Swift/BAT did not localize GRB 240306A onboard (T0: 2024-03-06T06:45:49.58 UTC, Fermi/GBM trigger 731400355).

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-100,+100] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 14 in a 2.048 s analysis time bin, starting at T0 + 0.512 s.

NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT coded FOV, with a DeltaLLHOut of 1.86.

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.swift.psu.edu%2Fguano%2F&data=05%7C02%7Ccirculars%40gcn.nasa.gov%7C887a752fe810456574d308dc3dff6823%7C7005d45845be48ae8140d43da96dd17b%7C0%7C0%7C638453414370014126%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=9uFWgjFqiTq7UwRwDR3jCnnbjlNCgpcAfpIrKYtWGmc%3D&reserved=0


GRB_name: GRB240305A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35890
SUBJECT: Fermi GRB 240305A: Global MASTER-Net observations report
DATE:    24/03/06 19:30:41 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240305A ( Fermi GBM team, GCN 35869) errorbox  1 days 30310 sec after notice time and 1 days 30342 sec after trigger time at 2024-03-06 18:15:03 UT, with upper limit up to  19.4 mag. Observations started at twilight.  The observations began at zenith distance = 55 deg. The sun  altitude  is -14.9 deg. 

The galactic latitude b = -74 deg., longitude l = 279 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2391924

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

  116772 | 2024-03-06 18:15:03 |         MASTER-SAAO | (01h 52m 23.63s , -44d 32m 26.3s) |   C |    60 | 13.7 |        
  117330 | 2024-03-06 18:24:20 |         MASTER-SAAO | (01h 23m 00.92s , -38d 48m 51.7s) |   C |    60 | 12.3 |        
  118229 | 2024-03-06 18:39:19 |         MASTER-SAAO | (01h 36m 10.23s , -42d 27m 04.8s) |   C |    60 | 13.2 |        
  118229 | 2024-03-06 18:39:19 |         MASTER-SAAO | (01h 42m 50.95s , -42d 39m 23.8s) |   C |    60 | 15.1 |        
  118309 | 2024-03-06 18:40:39 |         MASTER-SAAO | (01h 30m 42.38s , -38d 40m 29.4s) |   C |    60 | 14.5 |        
  118309 | 2024-03-06 18:40:39 |         MASTER-SAAO | (01h 37m 00.55s , -38d 52m 46.6s) |   C |    60 | 13.7 |        
  118388 | 2024-03-06 18:41:59 |         MASTER-SAAO | (01h 20m 49.84s , -46d 15m 01.5s) |   C |    60 | 16.2 |        
  118388 | 2024-03-06 18:41:59 |         MASTER-SAAO | (01h 27m 56.71s , -46d 27m 27.1s) |   C |    60 | 15.7 |        
  118468 | 2024-03-06 18:43:19 |         MASTER-SAAO | (00h 54m 49.20s , -42d 27m 18.8s) |   C |    60 | 17.2 |        
  118468 | 2024-03-06 18:43:19 |         MASTER-SAAO | (01h 01m 28.21s , -42d 39m 44.6s) |   C |    60 | 15.0 |        
  118548 | 2024-03-06 18:44:38 |         MASTER-SAAO | (01h 39m 17.93s , -44d 20m 50.7s) |   C |    60 | 15.4 |        
  118548 | 2024-03-06 18:44:38 |         MASTER-SAAO | (01h 46m 10.88s , -44d 33m 13.0s) |   C |    60 | 15.3 |        
  118627 | 2024-03-06 18:45:58 |         MASTER-SAAO | (00h 56m 45.33s , -44d 21m 16.1s) |   C |    60 | 18.3 |        
  118627 | 2024-03-06 18:45:58 |         MASTER-SAAO | (01h 03m 37.12s , -44d 33m 43.9s) |   C |    60 | 18.3 |        
  118707 | 2024-03-06 18:47:18 |         MASTER-SAAO | (00h 53m 11.03s , -40d 34m 12.1s) |   C |    60 | 19.2 |        
  118707 | 2024-03-06 18:47:18 |         MASTER-SAAO | (00h 59m 38.30s , -40d 46m 36.9s) |   C |    60 | 19.4 |        
  118787 | 2024-03-06 18:48:38 |         MASTER-SAAO | (01h 15m 34.39s , -42d 28m 26.0s) |   C |    60 | 19.4 |        
  118787 | 2024-03-06 18:48:38 |         MASTER-SAAO | (01h 22m 13.76s , -42d 40m 50.0s) |   C |    60 | 19.3 |        
  118866 | 2024-03-06 18:49:57 |         MASTER-SAAO | (01h 13m 16.50s , -40d 32m 48.9s) |   C |    60 | 19.3 |        
  118866 | 2024-03-06 18:49:57 |         MASTER-SAAO | (01h 19m 43.99s , -40d 45m 11.2s) |   C |    60 | 19.3 |        
  118946 | 2024-03-06 18:51:17 |         MASTER-SAAO | (01h 18m 00.60s , -44d 22m 20.9s) |   C |    60 | 19.4 |        
  118946 | 2024-03-06 18:51:17 |         MASTER-SAAO | (01h 24m 52.76s , -44d 34m 46.7s) |   C |    60 | 19.4 |        
  119026 | 2024-03-06 18:52:37 |         MASTER-SAAO | (01h 33m 22.27s , -40d 32m 35.9s) |   C |    60 | 19.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240306A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35891
SUBJECT: Fermi GRB 240306A: Global MASTER-Net observations report
DATE:    24/03/06 19:30:53 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240306A ( Fermi GBM team, GCN 35885) errorbox  41878 sec after notice time and 41910 sec after trigger time at 2024-03-06 18:24:20 UT, with upper limit up to  19.4 mag. Observations started at twilight.  The observations began at zenith distance = 64 deg. The sun  altitude  is -16.8 deg. 

The galactic latitude b = -74 deg., longitude l = 280 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2392907

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   41941 | 2024-03-06 18:24:20 |         MASTER-SAAO | (01h 23m 00.92s , -38d 48m 51.7s) |   C |    60 | 12.3 |        
   42840 | 2024-03-06 18:39:19 |         MASTER-SAAO | (01h 36m 10.23s , -42d 27m 04.8s) |   C |    60 | 13.2 |        
   42840 | 2024-03-06 18:39:19 |         MASTER-SAAO | (01h 42m 50.95s , -42d 39m 23.8s) |   C |    60 | 15.1 |        
   42920 | 2024-03-06 18:40:39 |         MASTER-SAAO | (01h 30m 42.38s , -38d 40m 29.4s) |   C |    60 | 14.5 |        
   42920 | 2024-03-06 18:40:39 |         MASTER-SAAO | (01h 37m 00.55s , -38d 52m 46.6s) |   C |    60 | 13.7 |        
   42999 | 2024-03-06 18:41:59 |         MASTER-SAAO | (01h 20m 49.84s , -46d 15m 01.5s) |   C |    60 | 16.2 |        
   42999 | 2024-03-06 18:41:59 |         MASTER-SAAO | (01h 27m 56.71s , -46d 27m 27.1s) |   C |    60 | 15.7 |        
   43079 | 2024-03-06 18:43:19 |         MASTER-SAAO | (00h 54m 49.20s , -42d 27m 18.8s) |   C |    60 | 17.2 |        
   43079 | 2024-03-06 18:43:19 |         MASTER-SAAO | (01h 01m 28.21s , -42d 39m 44.6s) |   C |    60 | 15.0 |        
   43159 | 2024-03-06 18:44:38 |         MASTER-SAAO | (01h 39m 17.93s , -44d 20m 50.7s) |   C |    60 | 15.4 |        
   43159 | 2024-03-06 18:44:38 |         MASTER-SAAO | (01h 46m 10.88s , -44d 33m 13.0s) |   C |    60 | 15.3 |        
   43238 | 2024-03-06 18:45:58 |         MASTER-SAAO | (00h 56m 45.33s , -44d 21m 16.1s) |   C |    60 | 18.3 |        
   43238 | 2024-03-06 18:45:58 |         MASTER-SAAO | (01h 03m 37.12s , -44d 33m 43.9s) |   C |    60 | 18.3 |        
   43318 | 2024-03-06 18:47:18 |         MASTER-SAAO | (00h 53m 11.03s , -40d 34m 12.1s) |   C |    60 | 19.2 |        
   43318 | 2024-03-06 18:47:18 |         MASTER-SAAO | (00h 59m 38.30s , -40d 46m 36.9s) |   C |    60 | 19.4 |        
   43398 | 2024-03-06 18:48:38 |         MASTER-SAAO | (01h 15m 34.39s , -42d 28m 26.0s) |   C |    60 | 19.4 |        
   43398 | 2024-03-06 18:48:38 |         MASTER-SAAO | (01h 22m 13.76s , -42d 40m 50.0s) |   C |    60 | 19.3 |        
   43477 | 2024-03-06 18:49:57 |         MASTER-SAAO | (01h 13m 16.50s , -40d 32m 48.9s) |   C |    60 | 19.3 |        
   43477 | 2024-03-06 18:49:57 |         MASTER-SAAO | (01h 19m 43.99s , -40d 45m 11.2s) |   C |    60 | 19.3 |        
   43557 | 2024-03-06 18:51:17 |         MASTER-SAAO | (01h 18m 00.60s , -44d 22m 20.9s) |   C |    60 | 19.4 |        
   43557 | 2024-03-06 18:51:17 |         MASTER-SAAO | (01h 24m 52.76s , -44d 34m 46.7s) |   C |    60 | 19.4 |        
   43637 | 2024-03-06 18:52:37 |         MASTER-SAAO | (01h 33m 22.27s , -40d 32m 35.9s) |   C |    60 | 19.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240306A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35892
SUBJECT: GRB 240306A: AstroSat CZTI detection
DATE:    24/03/07 08:00:05 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240306A which was also detected by Fermi-GBM (Fermi GBM team, GCN Circ. 35885), and Swift-BAT (Parsotan et al., GCN Circ. 35889).

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-03-06 06:45:51.65 UTC. The measured peak count rate associated with the burst is 256 (+160, -4) counts/s above the background in the combined data of all quadrants, with a total of 633 (+225, -236) counts. The local mean background count rate was 301 (+7, -9) counts/s. We caution that there is a 0.3 s readout dead time in CZTI data during the burst which affects the calculated total count rate. Using cumulative rates, we measure a T90 of 7.1 (+1.6, -2.4) s. 

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35894
SUBJECT: GRB 240229A: GRBAlpha detection
DATE:    24/03/07 12:17:34 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The long-duration GRB 240229A (Fermi/GBM detection: GCN 35833; CALET/CGBM detection: GCN 35842; VZLUSAT-2 detection: GCN 35872; INTEGRAL/SPI-ACS peak detection at 2024-02-29 ~14:07:35 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract).

The detection was confirmed at the peak time 2024-02-29 14:07:33.5 UTC. The T90 duration measured by GRBAlpha is 24.5 s and the overall significance during T90 reaches 9 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240229A_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. 


GRB_name: GRB240227A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35896
SUBJECT: GRB 240227A (short): Glowbug gamma-ray detection
DATE:    24/03/07 14:42:02 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of the short GRB 240227A, which was also detected by Fermi/GBM, Konus/Wind, INTEGRAL/SPI-ACS, and BepiColombo (GCN 35814, 35821, 35871, 35874).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-02-27 04:40:14.152 with a duration of 0.51 s and a total significance of about 16.3 sigma.  The light curve comprises a single peak.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=1.0 and a cutoff energy ("Epeak") of 576 keV.  The modeled 10-10000 keV fluence is 1.5e-06 erg/cm^2.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35897
SUBJECT: GRB 240229A: Glowbug gamma-ray detection
DATE:    24/03/07 14:43:24 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240229A, which was also detected by Fermi/GBM (GCN 35833, 35834), CALET (GCN 35842), INTEGRAL/SPI-ACS, Konus/Wind, BepiColombo (GCN 35870), VZLUSAT-2 (GCN 35872), and GRBAlpha (GCN 35894).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-02-29 14:07:09.552 with a duration of 24.6 s and a total significance of about 27.0 sigma. The light curve comprises two primary peaks at ~T0+3s and ~T0+23s.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission in two defined intervals from T0 to T0+10.2s and T0+20.5s to +24.6s resulted respectively in photon indices dN/dE~E^x of x=0.5 and x=1.5, and cutoff energies ("Epeak") of 728 keV and 439 keV.  The respective modeled 10-10000 keV fluences are 3.9e-06 erg/cm^2 and 9.6e-07 erg/cm^2.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240306A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35899
SUBJECT: GRB 240306A: Fermi GBM observation
DATE:    24/03/07 15:53:40 GMT
FROM:    Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 06:45:50.21 UT on 06 March 2024, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 240306A (trigger 731400355 / 240306282),
which was also detected by the Swift/BAT GUANO (Parsotan et al. 2024, GCN 35889),
AstroSat CZTI (Joshi et al. 2024, GCN 35892) and INTEGRAL SPI-ACS (trigger 10616).

The GBM localization was reported in an earlier GCN (Fermi GBM Team, GCN 35885).

The angle from the Fermi LAT boresight at the GBM trigger time is 87 degrees.

The GBM light curve consists of single pulse 
with a duration (T90) of about 9 s (50-300 keV).
The time-averaged spectrum from T0-1.7 s to T0+7.7 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.16 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 135 +/- 12 keV.

The event fluence (10-1000 keV) in this time interval is
(3.15 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux 
measured starting from T0+0.6 s in the 10-1000 keV band
is 6.8 +/- 0.3 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB231215A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35900
SUBJECT: GRB 231215A: further radio observations with the VLA
DATE:    24/03/08 07:53:00 GMT
FROM:    Stefano Giarratana at University of Bologna <s.giarratana@ira.inaf.it>

S. Giarratana (University of Bologna, INAF-IRA), M. Giroletti
(INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.),
N. Omodei (Stanford Univ.)


At 02:46:36 UT on 2023 December 28 (T_mid = 12.7 days post-burst) 
and at 01:39:51 UT on 2024 January 17 (T_mid = 32.7 days 
post-burst) the Karl G. Jansky VLA observed the field of
GRB 231215A (D'Avanzo et al., GCN 35343) at a central frequency
of 6 and 10 GHz. 

The standard J0542+4951 was used as bandpass and flux density
calibrator, while J0102+5824 was used as phase calibrator.

From a preliminary analysis, the radio source coincident with
GRB 231215A (Rhodes et al., GCN 35397; Giarratana et al., GCN 35507)
is still detected. We derive the following surface brightness
peak estimates.

================================================================
T_mid    Freq     Peak     r.m.s.   Beam         PA
[days]   [GHz]    [uJy/b]  [uJy/b] [arcsec]     [deg]
================================================================
12.7     6        110      8        11.69x9.50   -44
12.7     10       127      7        7.06x5.79    -33
32.7     6        48       7        7.34x4.23    -31
32.7     10       62       6        5.27x3.13    -24
================================================================

We would like to thank the staff of the VLA for approving, executing,
and processing the observations.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc.

These observations were carried out as part of project SF161095,
approved in the framework of the Fermi - NRAO joint program agreement.


GRB_name: GRB240308A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35902
SUBJECT: GRB 240308A: Fermi GBM Final Localization
DATE:    24/03/08 14:47:01 GMT
FROM:    Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi@ba.infn.it>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 06:25:22.05 UT on 08 March 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240308A (trigger 731571927 / 240308268).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 77.89, Dec = 50.92 (J2000 degrees, equivalent to J2000 05h 11m, 50d 55'),
with a statistical uncertainty of Error Radius = 4.56 degrees.

The angle from the Fermi LAT boresight is 25 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240308268/quicklook/glg_skymap_all_bn240308268.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240308268/quicklook/glg_healpix_all_bn240308268.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240308268/quicklook/glg_lc_medres34_bn240308268.gif"


GRB_name: GRB240229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35903
SUBJECT: GRID detection of GRB 240229A
DATE:    24/03/08 16:39:27 GMT
FROM:    GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>

Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration:


GRID-03B and GRID-04 report the detection of the long-duration GRB 240229A, which was also detected by Fermi/GBM, CALET VZLUSAT-2, GRBAlpha and Glowbug (GCN Circular 35833, 35842, 35872, 35894 and 35897).


The event was triggered with GRID on 2024-02-29 at 14:07:08 UTC and had a double-peak structure. The measured burst duration (T90) in the 30-2000 keV range is approximately 25.0 Â± 3.0 seconds.

The time-averaged spectrum of the first peak using GRID-04 realtime data from T+0 to T+10 sec is best fit by a power-law model with a fluence in the 10-1000 keV band is about 3.5259E-05 erg/cm2. The powerlaw index of the time-averaged spectrum is -1.51(-0.06,+0.06). All the quoted errors are at the 1-sigma confidence level.


GRB_name: GRB240229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35904
SUBJECT: GRID detection of GRB 240229A (Updated Report)
DATE:    24/03/08 16:54:57 GMT
FROM:    GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>

Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration:

GRID-03B and GRID-04 report the detection of the long-duration GRB 240229A, which was also detected by Fermi/GBM, CALET VZLUSAT-2, GRBAlpha and Glowbug (GCN Circular 35833, 35842, 35872, 35894 and 35897).

The event was triggered with GRID on 2024-02-29 at 14:07:08 UTC and had a double-peak structure. The measured burst duration (T90) in the 30-2000 keV range is approximately 25.0 Â± 3.0 seconds.

The time-averaged spectrum of the first peak using GRID-04 realtime data from T+0 to T+10 sec is best fit by a power-law model with a fluence in the 10-1000 keV band is about 3.5259E-05 erg/cm2. The powerlaw index of the time-averaged spectrum is -1.51(-0.06,+0.06). All the quoted errors are at the 1-sigma confidence level.

The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB240229A/GRID_240229A_ltcv.pdf. The GRID spectrum of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB240229A/GRID_240229A_spec_pl.pdf.

GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.


GRB_name: GRB240309A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35907
SUBJECT: GRB 240309A: MAXI/GSC detection
DATE:    24/03/10 00:51:38 GMT
FROM:    Motoko Serino at Aoyama Gakuin U. <serino@phys.aoyama.ac.jp>

M. Shidatsu (Ehime U.), M. Serino (AGU), M. Nakajima (Nihon U.), Y. Kawakubo (LSU),
H. Negoro, K. Kobayashi, M. Tanaka, Y. Soejima, Y. Kudo (Nihon U.), 
T. Mihara, T. Kawamuro, S. Yamada, S. Wang, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), 
T. Sakamoto, S. Sugita, H. Hiramatsu, H. Nishikawa, A. Yoshida (AGU), 
Y. Tsuboi, S. Urabe, S. Nawa, N. Nemoto, E.Goto (Chuo U.), 
Y. Niida (Ehime U.),
I. Takahashi, M. Niwano, S. Sato, N. Higuchi, Y. Yatsu (Tokyo Tech), 
S. Nakahira,  S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, T. Kurihara (JAXA), 
Y. Ueda, K. Setoguchi, T. Yoshitake, Y. Nakatani, Y. Okada (Kyoto U.), 
M. Yamauchi, Y. Hagiwara, Y. Otsuki, T. Hasegawa, M. Nishio (Miyazaki U.), 
K. Yamaoka (Nagoya U.),
M. Sugizaki (NAOC),
W. Iwakiri (Chiba U.) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source 
at 21:33:07 UT on March 9, 2024.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (241.601 deg, -69.000 deg) = (16 06 24, -69 00 00) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.34 deg and 0.23 deg, respectively.
The roll angle of long axis from the north direction is 99.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 158 +- 29 mCrab
(4.0-10.0keV, 1 sigma error).
Without assumptions on the source constancy, we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (242.811, -67.736) deg = (16 11 14, -67 44 09) (J2000)
(R.A., Dec) = (241.055, -67.657) deg = (16 04 13, -67 39 25) (J2000)
(R.A., Dec) = (240.086, -70.134) deg = (16 00 20, -70 08 02) (J2000)
(R.A., Dec) = (242.048, -70.222) deg = (16 08 11, -70 13 19) (J2000)
There was no significant excess flux in the previous transit at 20:00 UT
and in the next transit at 23:06 UT with an upper limit of 20 mCrab for each.


GRB_name: GRB240310A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35908
SUBJECT: GRB 240310A: Fermi GBM Final Real-time Localization
DATE:    24/03/10 05:50:42 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 05:40:08 UT on 10 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240310A (trigger 731742013.593492 / 240310236).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 312.5, Dec = -4.9 (J2000 degrees, equivalent to J2000 20h 49m, -4d 54'), with a statistical uncertainty of 10.5 degrees.

The angle from the Fermi LAT boresight is 87.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240310236/quicklook/glg_skymap_all_bn240310236.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240310236/quicklook/glg_healpix_all_bn240310236.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240310236/quicklook/glg_lc_medres34_bn240310236.gif


GRB_name: GRB240303C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35915
SUBJECT: GRB 240303C: VZLUSAT-2 detection
DATE:    24/03/12 19:07:08 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),  N. Werner  (Masaryk U.), M. Ohno (Hiroshima U.),  L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU)  -- the VZLUSAT-2/GRB payload collaboration.

The long-duration GRB 240303C (Fermi/GBM detection: trigger no. 731189113; Konus/Wind detection trigger at 2024-03-03 20:05:07.253 UT) was detected by the GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).

The data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2024-03-03 20:04:53 (20:04:52) UTC. The T90 duration is 5 s (3 s) and the significance during T90 reaches 7.8 sigma (5.7 sigma) for detector unit no. 0 (no. 1).

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB240303C_GCN_VZLUSAT2.pdf

We note that the light curve measured by VZLUSAT-2 is shifted by approximately 18 s with respect to light curves obtained by other missions. At the moment, the cause of this discrepancy is being investigated.

All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.


GRB_name: GRB240312A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35917
SUBJECT: GRB 240312A: GECAM detection of a long burst 
DATE:    24/03/13 03:12:08 GMT
FROM:    wenlongzhang2018@163.com

Wen-Long Zhang, Shao-Lin Xiong, Xiao-Yun Zhao report on behalf of the GECAM team:

GECAM-B was triggered in-flight by a long burst, GRB 240312A, at 2024-03-12T14:02:10.550 UTC (T0). INTEGRAL/SPI-ACS was also triggered by this burst. 

According to the GECAM-B light curves, this burst shows single-pulses with a total duration of ~5 sec.

According to the in-flight software, GECAM-B localized this burst to the following position (J2000): 
Ra: 13.86 deg    
Dec: 2.45 deg
Err: 2.74 deg (1-sigma, statistical only)

The time-averaged spectrum of GECAM-B realtime data from about T0-0.2 to T0+3.8 s could be
adequately fit by a Band function with a flux about 2.09E-6 erg/cm^2/s in 20-1000 keV. 

We note that these results are very preliminary. Refined analysis will be reported later.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in December 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).


GRB_name: GRB240312A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35921
SUBJECT: GRB 240312A: Glowbug gamma-ray detection
DATE:    24/03/13 19:21:31 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240312A, which was also detected by GECAM-B (GCN 35917) and INTEGRAL/SPI-ACS (Trigger 10625).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-12 14:02:09.584 with a duration of 2.0 s and a total significance of about 8.1 sigma.  The light curve comprises a single peak.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a poorly constrained power-law index and a cutoff energy ("Epeak") of 185 keV.  The modeled 10-10000 keV fluence is 2.7e-07 erg/cm^2.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited


GRB_name: GRB240204A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35922
SUBJECT: GRB240204A: VIRT optical upper limit
DATE:    24/03/14 00:11:58 GMT
FROM:    Priya Gokuldass at ERAU <gokuldap@my.erau.edu>

K. Smith (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), D. Morris (NASA), T. Lombardi (Eckerd College), K. Noonan (UVI), R. Querrard (UVI), D. Smith (UVI) report:

We observed the field of GRB240204A (Cenko et al., GCN 35666) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 02-05-2024 starting at 00:36:35 (T+10.04 hrs). We performed a series of exposures in an R filter with a total exposure of 4000s. The weather conditions were clear during the hours of observation with an average airmass of 1.08. 

We do not detect any source within the enhanced XRT position (Beardmore  et al. GCN 35671). This non-detection is consistent with the upper limits and detections of the faint optical transient reported by Master (Lipunov et al., GCN 35668),  Mondy (Pozanenko et al., GCN 35670), Montarrenti Observatory (Leonini et al., GCN 35672), LCOGT (Perez-Fournon and Poidevin, GCN 35673), Osservatorio Nastro Verde (Ruocco et al., GCN 35677), Liverpool Telescope (Bochenek et al., GCN 35678), and Observatoire de Haute-Provence (Adami et al., GCN 35690). We report the following 3-sigma upper limit:

T_mid             ||Exposure   ||Filter   ||Limit 
T+ 10.04 hrs      || 4000s     || R       || >20.9

The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. The VIRT is still in the commissioning phase. 

We acknowledge financial support from NASA MUREP MIRO award 80NSSC21M0001 and NASA EPSCoR award 80NNSC22M0063. R.Q and N.B.O also acknowledge financial support from South Carolina Space Grant award 80NSSC20M0054. This message can be cited.


GRB_name: GRB240314A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35924
SUBJECT: Fermi GRB 240314A: Global MASTER-Net observations report
DATE:    24/03/14 12:45:42 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240314A ( Fermi GBM team, GCN 35923) errorbox  2094 sec after notice time and 2130 sec after trigger time at 2024-03-14 12:06:38 UT, with upper limit up to  21.0 mag. Observations started at twilight.  The observations began at zenith distance = 49 deg. The sun  altitude  is -9.8 deg. 

The galactic latitude b = 44 deg., longitude l = 208 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2399137

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    2161 | 2024-03-14 12:06:38 |        MASTER-Tunka | (09h 38m 21.12s , +19d 35m 30.4s) |   C |    60 | 14.0 |        
    2240 | 2024-03-14 12:07:57 |        MASTER-Tunka | (09h 46m 47.30s , +19d 34m 19.2s) |   C |    60 | 13.9 |        
    2319 | 2024-03-14 12:09:16 |        MASTER-Tunka | (09h 47m 39.13s , +17d 41m 52.7s) |   C |    60 | 14.3 |        
    2636 | 2024-03-14 12:14:33 |        MASTER-Tunka | (09h 54m 28.40s , +19d 34m 23.7s) |   C |    60 | 13.9 |        
    2795 | 2024-03-14 12:17:12 |        MASTER-Tunka | (09h 54m 09.79s , +23d 22m 51.5s) |   C |    60 | 13.2 |        
    2874 | 2024-03-14 12:18:31 |        MASTER-Tunka | (10h 02m 58.51s , +23d 23m 58.1s) |   C |    60 | 13.7 |        
    2954 | 2024-03-14 12:19:51 |        MASTER-Tunka | (09h 36m 11.27s , +13d 55m 07.8s) |   C |    60 | 14.0 |        
    3270 | 2024-03-14 12:25:07 |        MASTER-Tunka | (09h 47m 39.73s , +17d 42m 53.7s) |   C |    60 | 14.1 |        
    3349 | 2024-03-14 12:26:26 |        MASTER-Tunka | (09h 56m 05.28s , +17d 41m 17.0s) |   C |    60 | 14.4 |        
    3588 | 2024-03-14 12:30:25 |        MASTER-Tunka | (09h 54m 28.29s , +19d 37m 08.1s) |   C |    60 | 14.4 |        
    3746 | 2024-03-14 12:33:03 |        MASTER-Tunka | (09h 54m 06.55s , +23d 23m 18.0s) |   C |    60 | 15.5 |        
    3825 | 2024-03-14 12:34:22 |        MASTER-Tunka | (10h 02m 58.89s , +23d 23m 11.0s) |   C |    60 | 13.8 |        
    3905 | 2024-03-14 12:35:42 |        MASTER-Tunka | (09h 36m 15.10s , +13d 55m 44.7s) |   C |    60 | 14.8 |        
    4063 | 2024-03-14 12:38:20 |        MASTER-Tunka | (09h 38m 21.67s , +19d 37m 46.3s) |   C |    60 | 14.8 |        
    4142 | 2024-03-14 12:39:39 |        MASTER-Tunka | (09h 46m 48.16s , +19d 36m 46.6s) |   C |    60 | 21.0 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240317B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35941
SUBJECT: GRB 240317B: Fermi GBM Final Real-time Localization
DATE:    24/03/17 11:04:59 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 10:54:24 UT on 17 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240317B (trigger 732365669.017448 / 240317454).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 274.5, Dec = 49.6 (J2000 degrees, equivalent to J2000 18h 18m, 49d 36'), with a statistical uncertainty of 8.8 degrees.

The angle from the Fermi LAT boresight is 96.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240317454/quicklook/glg_skymap_all_bn240317454.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240317454/quicklook/glg_healpix_all_bn240317454.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240317454/quicklook/glg_lc_medres34_bn240317454.gif


GRB_name: GRB240317A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35942
SUBJECT: Fermi GRB 240317A: Global MASTER-Net observations report
DATE:    24/03/17 13:31:01 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 240317A ( Fermi GBM team, GCN 35939) errorbox  12523 sec after notice time and 12555 sec after trigger time at 2024-03-17 13:13:10 UT, with upper limit up to  17.8 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -32.2 deg. 

MASTER-Tunka robotic telescope  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240317A errorbox  13217 sec after notice time and 13249 sec after trigger time at 2024-03-17 13:24:45 UT, with upper limit up to  13.5 mag. The observations began at zenith distance = 80 deg. The sun  altitude  is -20.7 deg. 

The galactic latitude b = 60 deg., longitude l = 24 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2400638

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   12585 | 2024-03-17 13:13:10 |         MASTER-Amur | (14h 48m 33.06s , +20d 16m 10.5s) |   C |    60 | 17.7 |        
   12665 | 2024-03-17 13:14:30 |         MASTER-Amur | (14h 57m 03.77s , +20d 17m 46.4s) |   C |    60 | 17.4 |        
   12745 | 2024-03-17 13:15:50 |         MASTER-Amur | (14h 59m 54.03s , +22d 11m 46.7s) |   C |    60 | 17.6 |        
   12825 | 2024-03-17 13:17:10 |         MASTER-Amur | (15h 08m 25.81s , +22d 11m 31.4s) |   C |    60 | 17.4 |        
   13067 | 2024-03-17 13:21:11 |         MASTER-Amur | (14h 38m 28.91s , +18d 21m 26.0s) |   C |    60 | 17.8 |        
   13146 | 2024-03-17 13:22:31 |         MASTER-Amur | (14h 46m 52.55s , +18d 23m 18.1s) |   C |    60 | 17.7 |        
   13280 | 2024-03-17 13:24:45 |        MASTER-Tunka | (14h 41m 05.02s , +21d 19m 39.8s) |   C |    60 | 13.5 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240317B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35943
SUBJECT: Fermi GRB 240317B: Global MASTER-Net observations report
DATE:    24/03/17 13:31:09 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 240317B ( Fermi GBM team, GCN 35941) errorbox  465 sec after notice time and 497 sec after trigger time at 2024-03-17 11:02:41 UT, with upper limit up to  17.7 mag. Observations started at twilight.  The observations began at zenith distance = 69 deg. The sun  altitude  is -14.2 deg. 

MASTER-Tunka robotic telescope  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240317B errorbox  5026 sec after notice time and 5058 sec after trigger time at 2024-03-17 12:18:42 UT, with upper limit up to  14.5 mag. Observations started at twilight.  The observations began at zenith distance = 78 deg. The sun  altitude  is -10.9 deg. 

The galactic latitude b = 25 deg., longitude l = 78 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2400679

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     527 | 2024-03-17 11:02:41 |         MASTER-Amur | (18h 08m 33.84s , +60d 12m 29.5s) |   C |    60 | 17.0 |        
     607 | 2024-03-17 11:04:01 |         MASTER-Amur | (18h 24m 41.82s , +60d 10m 12.2s) |   C |    60 | 17.1 |        
    5088 | 2024-03-17 12:18:42 |        MASTER-Tunka | (18h 40m 58.76s , +51d 03m 11.4s) |   C |    60 | 13.3 |        
    5247 | 2024-03-17 12:21:20 |        MASTER-Tunka | (18h 38m 56.08s , +52d 56m 32.7s) |   C |    60 | 13.1 |        
    5326 | 2024-03-17 12:22:39 |        MASTER-Tunka | (18h 11m 57.74s , +54d 49m 55.0s) |   C |    60 | 13.6 |        
    5405 | 2024-03-17 12:23:59 |        MASTER-Tunka | (18h 25m 29.46s , +54d 49m 03.5s) |   C |    60 | 13.1 |        
    5484 | 2024-03-17 12:25:18 |        MASTER-Tunka | (18h 44m 12.61s , +49d 08m 38.9s) |   C |    60 | 12.8 |        
    5723 | 2024-03-17 12:29:16 |        MASTER-Tunka | (18h 10m 46.74s , +56d 42m 59.1s) |   C |    60 | 13.9 |        
    5809 | 2024-03-17 12:30:42 |        MASTER-Tunka | (18h 25m 14.42s , +56d 44m 15.4s) |   C |    60 | 13.9 |        
    5888 | 2024-03-17 12:32:02 |        MASTER-Tunka | (18h 37m 57.53s , +54d 50m 37.3s) |   C |    60 | 13.9 |        
    5967 | 2024-03-17 12:33:21 |        MASTER-Tunka | (18h 51m 38.66s , +54d 48m 51.4s) |   C |    60 | 13.8 |        
    6093 | 2024-03-17 12:35:27 |        MASTER-Tunka | (17h 32m 14.76s , +47d 49m 22.3s) |   C |    60 | 12.0 |        
    6173 | 2024-03-17 12:36:46 |        MASTER-Tunka | (17h 45m 53.62s , +51d 38m 34.6s) |   C |    60 | 13.6 |        
    6252 | 2024-03-17 12:38:05 |        MASTER-Tunka | (17h 58m 51.51s , +51d 37m 38.5s) |   C |    60 | 13.5 |        
    6331 | 2024-03-17 12:39:25 |        MASTER-Tunka | (18h 08m 20.83s , +53d 30m 31.9s) |   C |    60 | 13.5 |        
    6411 | 2024-03-17 12:40:44 |        MASTER-Tunka | (18h 22m 07.75s , +53d 30m 45.1s) |   C |    60 | 13.3 |        
    6490 | 2024-03-17 12:42:03 |        MASTER-Tunka | (17h 42m 29.98s , +53d 33m 01.3s) |   C |    60 | 13.7 |        
    6569 | 2024-03-17 12:43:22 |        MASTER-Tunka | (17h 56m 03.03s , +53d 31m 31.5s) |   C |    60 | 14.2 |        
    6648 | 2024-03-17 12:44:42 |        MASTER-Tunka | (18h 07m 12.93s , +55d 25m 21.8s) |   C |    60 | 13.5 |        
    6727 | 2024-03-17 12:46:01 |        MASTER-Tunka | (18h 21m 30.03s , +55d 25m 53.4s) |   C |    60 | 13.9 |        
    6807 | 2024-03-17 12:47:20 |        MASTER-Tunka | (18h 10m 40.47s , +51d 38m 42.8s) |   C |    60 | 12.5 |        
    6886 | 2024-03-17 12:48:40 |        MASTER-Tunka | (18h 34m 27.86s , +53d 30m 56.9s) |   C |    60 | 13.1 |        
    7045 | 2024-03-17 12:51:19 |        MASTER-Tunka | (18h 23m 52.08s , +51d 35m 59.6s) |   C |    60 | 12.9 |        
    7125 | 2024-03-17 12:52:38 |        MASTER-Tunka | (17h 45m 52.05s , +51d 36m 29.1s) |   C |    60 | 13.2 |        
    7283 | 2024-03-17 12:55:16 |        MASTER-Tunka | (18h 08m 31.13s , +53d 32m 30.1s) |   C |    60 | 12.0 |        
    7362 | 2024-03-17 12:56:36 |        MASTER-Tunka | (18h 22m 06.54s , +53d 30m 53.0s) |   C |    60 | 12.2 |        
    7442 | 2024-03-17 12:57:55 |        MASTER-Tunka | (17h 42m 28.24s , +53d 30m 30.9s) |   C |    60 | 13.5 |        
    7521 | 2024-03-17 12:59:15 |        MASTER-Tunka | (17h 56m 14.41s , +53d 31m 12.9s) |   C |    60 | 12.3 |        
    7600 | 2024-03-17 13:00:34 |        MASTER-Tunka | (18h 07m 15.33s , +55d 25m 54.0s) |   C |    60 | 13.1 |        
    7680 | 2024-03-17 13:01:53 |        MASTER-Tunka | (18h 21m 35.22s , +55d 24m 10.8s) |   C |    60 | 13.4 |        
    7838 | 2024-03-17 13:04:32 |        MASTER-Tunka | (18h 34m 26.84s , +53d 30m 37.4s) |   C |    60 | 12.8 |        
    7997 | 2024-03-17 13:07:11 |        MASTER-Tunka | (18h 01m 01.79s , +45d 53m 48.3s) |   C |    60 | 13.1 |        
    8116 | 2024-03-17 13:09:09 |         MASTER-Amur | (18h 08m 32.38s , +60d 15m 05.1s) |   C |    60 | 17.6 |        
    8168 | 2024-03-17 13:10:01 |        MASTER-Tunka | (17h 38m 59.01s , +45d 54m 53.6s) |   C |    60 | 12.7 |        
    8195 | 2024-03-17 13:10:29 |         MASTER-Amur | (18h 24m 43.45s , +60d 15m 58.2s) |   C |    60 | 17.7 |        
    8334 | 2024-03-17 13:12:48 |        MASTER-Tunka | (17h 26m 26.99s , +49d 44m 57.1s) |   C |    60 | 13.3 |        
    8414 | 2024-03-17 13:14:07 |        MASTER-Tunka | (17h 39m 06.53s , +49d 43m 35.7s) |   C |    60 | 13.6 |        
    8493 | 2024-03-17 13:15:26 |        MASTER-Tunka | (18h 23m 15.91s , +45d 53m 39.0s) |   C |    60 | 13.4 |        
    8572 | 2024-03-17 13:16:46 |        MASTER-Tunka | (17h 40m 10.09s , +55d 26m 08.0s) |   C |    60 | 13.2 |        
    8651 | 2024-03-17 13:18:05 |        MASTER-Tunka | (17h 54m 24.83s , +55d 25m 12.8s) |   C |    60 | 13.1 |        
    8730 | 2024-03-17 13:19:24 |        MASTER-Tunka | (17h 46m 22.65s , +44d 01m 00.9s) |   C |    60 | 14.5 |        
    8889 | 2024-03-17 13:22:03 |        MASTER-Tunka | (17h 21m 14.66s , +51d 37m 48.6s) |   C |    60 | 14.5 |        
    8968 | 2024-03-17 13:23:22 |        MASTER-Tunka | (17h 34m 22.92s , +51d 38m 11.6s) |   C |    60 | 13.6 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240315B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35946
SUBJECT: GRB 240315B: AstroSat CZTI detection
DATE:    24/03/17 16:20:24 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240315B.

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-03-15 21:46:05.50 UTC. The measured peak count rate associated with the burst is 74 (+33, -6) counts/s above the background in the combined data of three quadrants (out of four), with a total of 1069 (+247, -264) counts. The local mean background count rate was 209 (+2, -2) counts/s. Using cumulative rates, we measure a T90 of 34 (+3, -6) s.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-03-15 21:45:58.81 UTC. The measured peak count rate associated with the burst is 224 (+66, -32) counts/s above the background in the combined data of all quadrants, with a total of 2900 (+431, -469) counts. The local mean background count rate was 1256 (+4, -5) counts/s. We measure a T90 of 28 (+2, -3) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240317A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35947
SUBJECT: GRB 240317A: AstroSat CZTI detection
DATE:    24/03/17 16:22:39 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240317A which was also detected by Fermi GBM (Fermi-GBM team, GCN Circ. 35939).

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-03-17 09:44:00.50 UTC. The measured peak count rate associated with the burst is 216 (+47, -19) counts/s above the background in the combined data of all quadrants, with a total of 1230 (+201, -216) counts. The local mean background count rate was 383 (+3, -3) counts/s. Using cumulative rates, we measure a T90 of 10 (+2, -4) s. We caution that there is a 0.3 s readout dead time in CZTI data just after the burst. Hence, the T90 can be as large as 13 s for this GRB, with a lower limit of 6 s as estimated above by cumulative rates. 

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-03-17 09:43:58.74 UTC. The measured peak count rate associated with the burst is 408 (+77, -67) counts/s above the background in the combined data of all quadrants, with a total of 2969 (+539, -536) counts. The local mean background count rate was 1833 (+8, -9) counts/s. We measure a T90 of 17 (+3, -4) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240317B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35948
SUBJECT: GRB 240317B: Swift/BAT-GUANO arcminute localization of a burst
DATE:    24/03/18 00:22:44 GMT
FROM:    Aaron Tohuvavohu at University of Toronto <aaron.tohu@gmail.com>

James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC)  report:

Swift/BAT did not localize GRB 240317B onboard (T0: 2024-03-17T10:54:24.00 UTC, Fermi/GBM trigger 732365669).

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), detects the burst in a 16.384 s analysis time bin with a sqrt(TS) of 49.27.
An arcminute localization is found with DeltaLLHOut of 385 and a DeltaLLHPeak of 501.

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

The BAT position is
RA, Dec = 272.18, +39.182 deg which is
   RA(J2000)  = 18h 08m 43.2s
   Dec(J2000) = +39d 10â€² 55.2â€³
with an estimated uncertainty of 15 arcmin radius, due to star tracker loss-of-lock.

Follow-up observations from other instruments are requested.
XRT and UVOT will not follow-up until March 18 due to planned observatory downtime.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB240318A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35949
SUBJECT: GRB 240318A: Fermi GBM Final Real-time Localization
DATE:    24/03/18 03:01:31 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 02:51:01 UT on 18 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240318A (trigger 732423066.81932 / 240318119).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 275.1, Dec = -5.0 (J2000 degrees, equivalent to J2000 18h 20m, -5d 00'), with a statistical uncertainty of 4.8 degrees.

The angle from the Fermi LAT boresight is 53.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240318119/quicklook/glg_skymap_all_bn240318119.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240318119/quicklook/glg_healpix_all_bn240318119.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240318119/quicklook/glg_lc_medres34_bn240318119.gif


GRB_name: GRB240318A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35950
SUBJECT: Fermi GRB 240318A: Global MASTER-Net observations report
DATE:    24/03/18 03:30:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240318A ( Fermi GBM team, GCN 35949) errorbox  45 sec after notice time and 77 sec after trigger time at 2024-03-18 02:52:19 UT, with upper limit up to  16.6 mag. Observations started at twilight.  The observations began at zenith distance = 55 deg. The sun  altitude  is -11.1 deg. 

MASTER-SAAO robotic telescope  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240318A errorbox  52 sec after notice time and 84 sec after trigger time at 2024-03-18 02:52:25 UT, with upper limit up to  17.6 mag. The observations began at zenith distance = 47 deg. The sun  altitude  is -23.4 deg. 

The galactic latitude b =  4 deg., longitude l = 25 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2401036

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

      88 | 2024-03-18 02:52:19 |      MASTER-Tavrida | (18h 47m 01.74s , -04d 52m 07.6s) |   C |    20 | 16.5 |        
      94 | 2024-03-18 02:52:25 |         MASTER-SAAO | (18h 42m 40.28s , -05d 38m 11.7s) |   C |    20 | 17.5 |        
      94 | 2024-03-18 02:52:25 |         MASTER-SAAO | (18h 40m 48.53s , -05d 24m 58.7s) |   C |    20 | 17.4 |        
     117 | 2024-03-18 02:52:48 |      MASTER-Tavrida | (18h 47m 05.23s , -04d 51m 08.3s) |   C |    20 | 16.5 |        
     134 | 2024-03-18 02:53:05 |         MASTER-SAAO | (18h 42m 40.33s , -05d 38m 08.3s) |   C |    20 | 17.5 |        
     134 | 2024-03-18 02:53:05 |         MASTER-SAAO | (18h 40m 48.53s , -05d 24m 54.8s) |   C |    20 | 17.4 |        
     149 | 2024-03-18 02:53:16 |      MASTER-Tavrida | (18h 46m 58.27s , -04d 51m 41.1s) |   C |    30 | 16.6 |        
     178 | 2024-03-18 02:53:44 |         MASTER-SAAO | (18h 42m 40.38s , -05d 38m 05.3s) |   C |    30 | 17.6 |        
     178 | 2024-03-18 02:53:44 |         MASTER-SAAO | (18h 40m 48.53s , -05d 24m 51.9s) |   C |    30 | 17.6 |        
     187 | 2024-03-18 02:53:53 |      MASTER-Tavrida | (18h 46m 58.14s , -04d 50m 44.1s) |   C |    30 | 16.6 |        
     228 | 2024-03-18 02:54:29 |      MASTER-Tavrida | (18h 47m 04.89s , -04d 51m 46.9s) |   C |    40 | 16.6 |        
     232 | 2024-03-18 02:54:34 |         MASTER-SAAO | (18h 42m 40.45s , -05d 38m 02.3s) |   C |    40 | 17.6 |        
     232 | 2024-03-18 02:54:34 |         MASTER-SAAO | (18h 40m 48.53s , -05d 24m 48.9s) |   C |    40 | 17.6 |        
     282 | 2024-03-18 02:55:18 |      MASTER-Tavrida | (18h 46m 57.52s , -04d 52m 50.5s) |   C |    50 | 16.5 |        
     345 | 2024-03-18 02:56:16 |      MASTER-Tavrida | (18h 47m 03.45s , -04d 52m 44.2s) |   C |    60 | 16.5 |        
     648 | 2024-03-18 03:00:49 |      MASTER-Tavrida | (18h 22m 27.68s , -04d 26m 36.6s) |   C |   120 | 16.4 |        
     787 | 2024-03-18 03:02:59 |      MASTER-Tavrida | (18h 22m 25.32s , -04d 25m 45.6s) |   C |   140 | 16.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240317B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35955
SUBJECT: GRB 240317B: Fermi GBM Observation
DATE:    24/03/18 16:26:15 GMT
FROM:    rachel.hamburg@ijclab.in2p3.fr

R. Hamburg (CNRS/IN2P3/IJCLab) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 10:54:24.02 UT on 17 March 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240317B (trigger 732365669/240317454),
which was also detected by Swift/BAT-GUANO (DeLaunay et al. 2024, GCN 35948).
The Fermi GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 89 degrees.

The GBM light curve shows one main emission episode with a duration (T90)
of about 35 s (50-300 keV). The time-averaged spectrum
from T0-6.1 to T0+32.8 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.6 +/- 0.3 and the cutoff energy,
parameterized as Epeak, is 76 +/- 9 keV.

The event fluence (10-1000 keV) in this time interval is
(1.9 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.0 s in the 10-1000 keV band is 2.3 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB240318B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35957
SUBJECT: GRB 240318B: Glowbug gamma-ray detection
DATE:    24/03/18 18:58:31 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240318B.
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-18 06:50:23.312 with a duration of 12.3 s and a total significance of about 17.8 sigma.  The light curve comprises a single peak.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a poorly constrained power-law index and a cutoff energy ("Epeak") of ~1 MeV.  The modeled 10-10000 keV fluence is 2.3e-06 erg/cm^2.
 
The best-fit localization is RA, Decl. (J2000, deg) = 261.8, -12.0 with a radius of 19.9 deg (95% confidence), with a highly uncertain systematic uncertainty.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240317C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35958
SUBJECT: GRB 240317C: Glowbug gamma-ray detection
DATE:    24/03/18 18:59:53 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240317C.
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-17 20:20:25.304 with a duration of 8.2 s and a total significance of about 25.8 sigma.  The light curve comprises a single peak.
 
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a poorly constrained power-law index and a cutoff energy ("Epeak") of 216 keV.  The modeled 10-10000 keV fluence is 1.1e-06 erg/cm^2.
 
The best-fit localization is RA, Decl. (J2000, deg) = 314.8, -60.6  with a radius of 18.9 deg (95% confidence), with a highly uncertain systematic uncertainty.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240318A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35959
SUBJECT: GRB 240318A: Glowbug gamma-ray detection
DATE:    24/03/18 19:01:13 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240318A, which was also detected by Fermi/GBM (GCN 35949).

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-18 02:51:00.832 with a duration of 5.2 s and a total significance of about 14.4 sigma.  The light curve comprises a single peak.

Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a poorly constrained power-law index and a cutoff energy ("Epeak") of 163 keV.  The modeled 10-10000 keV fluence is 7.6e-07 erg/cm^2.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240317B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35965
SUBJECT: GRB 240317B: Swift/BAT-GUANO Angular Error Correction
DATE:    24/03/19 19:07:34 GMT
FROM:    Jimmy DeLaunay at Penn State <delauj2@gmail.com>

James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC)  report:

During the detection of GRB 240317B, Swift was in safe point mode and had an unstable pointing. Due to this, the angular error is larger than previously reported (GCN 35948). We have performed an imaging analysis at the time of the GRB and found Cyg X-1 at an angular offset of ~1 deg. We also attempt to approximately correct the best fit position. 

The updated BAT position and error is,
RA, Dec = 271.95, +38.4 deg which is
   RA(J2000)  = 18h 07m 48.0s
   Dec(J2000) = +38d 24â€² 00.0â€³
with an estimated uncertainty of ~1 deg radius


GRB_name: GRB240315C
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35966
SUBJECT: IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
DATE:    24/03/19 23:33:06 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

E. Burns on behalf of the IPN,

and

J. DeLaunay, A. Tohuvavohu, S. Barthelmy, J. Cummings, H. Krimm,
and D. Palmer on behalf of the Swift-BAT team, report:

The long-duration GRB 240315C has been detected by
Konus-Wind, in the waiting mode, and Swift (BAT),
so far, at about 73000 s UT (20:16:40).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a Konus-BAT annulus centered at
RA(2000)=159.341 deg (10h 37m 22s) Dec(2000)=+10.835 deg (+10d 50' 04")
whose radius is 26.696 +/- 26.696 deg (3 sigma).

This localization may be improved.

The fast X-ray transient EP240315a (Zhang et al., GCN 35931) is inside the annulus and is consisted with the Konus-Wind ecliptic latitude response, lending support to the association of GRB 240315C and the transient.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB240315_T73000/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN circular.


GRB_name: GRB240315C
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35971
SUBJECT: GRB 240315C / X-ray transient EP240315a: Swift/BAT detection
DATE:    24/03/21 15:47:43 GMT
FROM:    Jimmy DeLaunay at Penn State <delauj2@gmail.com>

James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Dmitry Svinkin (Ioffe Institute), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:

Swift/BAT did not localize GRB 240315C onboard (T0: 2024-03-15T20:10:44 UTC, EP240315a GCN 35931, GRB 240315C GCN 35966).

Swift/BAT detects the emission starting at ~T0 + 350 s and lasts for ~70 s. The rates data shows the emission through all energy bins, ranging from 15 keV to 350 keV. No formal spectral analysis has been performed, but the hardness seems to be in the typical range for GRBs. 

No event mode or survey mode data was available at the time due to being in a slew, so no imaging localization is possible.  


GRB_name: GRB240315C
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35972
SUBJECT: Konus-Wind detection of GRB 240315C (possible counterpart of EP240315a)
DATE:    24/03/21 16:05:26 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A.Lysenko, A. Ridnaia,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 240315C
(IPN triangulation: Svinkin et al., GCN 35966;
Swift-BAT detection: DeLaunay et al., GCN 35971)
was detected by Konus-Wind (KW) in the waiting mode
at T0=73018 s UT (20:16:58).

The burst was observed over the high and variable background
due to a solar particle event. A Bayesian block analysis of the KW waiting mode data in the 20-1600 keV band reveals a >20 sigma count rate increase in the interval from T0 to T0+47 s.
The burst light curve shows a multi-peaked structure with the brightest peak around ~T0+24 s (we note a 6 s gap in the data starting from ~T0+47 s).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240315_T73000/

The spectrum of the burst, measured from T0 to T0+47 s,
can be described by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.09(-0.25,+0.36) and Ep = 410(-159,+388) keV.

The spectrum near the peak count rate, measured from T0+15 s to T0+29 s,
can be described by a CPL model with
alpha = -0.80(-0.30,+0.38) and Ep = 459(-155,+304) keV.

The total burst fluence is 1.63(-0.40,+0.64)x10^-5 erg/cm^2,
and the 2.944 s peak energy flux, measured from T0+23 s,
is 9.13(-2.84,+3.65)x10^-7 erg/cm^2.
(both in the 20 keV - 10 MeV energy range).

The burst was detected ~374 s after the start time of the fast X-ray transient EP240315a (T0(EP)=20:10:44 UT; Zhang et al., GCN 35931) and during the ~1600 s interval of the transient activity. The positional (GCN 35966) and temporal coincidence of this burst with the transient
supports the conclusion that the EP240315a is the GRB counterpart.
Dimmer emission episodes of GRB 240315C may be missed by Konus-Wind due to the high and variable background.

Assuming GRB 240315C is indeed connected with EP240315a at
redshift z=4.859 (Saccardi et al., GCN 35936; Quirola-VÃ¡squez et al., GCN 35960) and a standard cosmology model with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is 7.1(-1.7,+2.8)x10^53 erg,
the peak luminosity L_iso is 2.3(-0.7,+0.9)x10^53 erg/s,
and the rest-frame peak energies of the time-integrated and
peak spectra, Ep,i,z = 2402(-932,+2273) keV and Ep,p,z = 2689(-902,+1781) keV, respectively.

With the obtained estimates, GRB 240315C is inside 90% prediction band for the 'Amati' relation and inside 90% prediction band for the 'Yonetoku' relation derived for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021),
see http://www.ioffe.ru/LEA/GRBs/GRB240315_T73000/GRB240315C_rest_frame.pdf


GRB_name: GRB240320A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35973
SUBJECT: Fermi GRB 240320A: Global MASTER-Net observations report
DATE:    24/03/21 17:46:02 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240320A ( Fermi GBM team, GCN 35967) errorbox  69145 sec after notice time and 69181 sec after trigger time at 2024-03-21 12:42:48 UT, with upper limit up to  18.2 mag. Observations started at twilight.  The observations began at zenith distance = 15 deg. The sun  altitude  is -13.5 deg. 

MASTER-Amur robotic telescope  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 240320A errorbox  80725 sec after notice time and 80760 sec after trigger time at 2024-03-21 15:55:48 UT, with upper limit up to  17.3 mag. The observations began at zenith distance = 30 deg. The sun  altitude  is -39.4 deg. 

The galactic latitude b = 45 deg., longitude l = 148 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2403375

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   69211 | 2024-03-21 12:42:48 |        MASTER-Tunka | (09h 10m 24.61s , +52d 39m 34.5s) |   C |    60 | 14.4 |        
   69335 | 2024-03-21 12:44:52 |        MASTER-Tunka | (09h 11m 55.93s , +50d 44m 36.9s) |   C |    60 | 14.3 |  Coadd 
   69600 | 2024-03-21 12:49:17 |        MASTER-Tunka | (08h 45m 24.19s , +52d 40m 17.4s) |   C |    60 | 15.9 |  Coadd 
   69698 | 2024-03-21 12:50:55 |        MASTER-Tunka | (09h 09m 31.06s , +54d 32m 15.0s) |   C |    60 | 16.5 |  Coadd 
   69797 | 2024-03-21 12:52:34 |        MASTER-Tunka | (08h 45m 26.41s , +52d 40m 09.6s) |   C |    60 | 16.9 |  Coadd 
   70044 | 2024-03-21 12:56:41 |        MASTER-Tunka | (09h 35m 38.76s , +54d 33m 26.0s) |   C |    60 | 16.1 |  Coadd 
   70162 | 2024-03-21 12:58:40 |        MASTER-Tunka | (08h 43m 21.21s , +54d 33m 41.9s) |   C |    60 | 15.6 |  Coadd 
   70282 | 2024-03-21 13:00:39 |        MASTER-Tunka | (09h 35m 39.14s , +54d 31m 37.8s) |   C |    60 | 14.8 |  Coadd 
   71463 | 2024-03-21 13:20:20 |        MASTER-Tunka | (09h 13m 48.63s , +48d 52m 15.6s) |   C |    60 | 13.9 |  Coadd 
   71922 | 2024-03-21 13:28:19 |        MASTER-Tunka | (08h 35m 26.53s , +60d 30m 49.8s) |   C |    20 | 18.2 |        
   72059 | 2024-03-21 13:30:16 |        MASTER-Tunka | (08h 49m 27.90s , +60d 06m 51.9s) |   C |    60 | 12.8 |  Coadd 
   72144 | 2024-03-21 13:31:41 |        MASTER-Tunka | (09h 12m 34.32s , +60d 05m 50.6s) |   C |    60 | 17.6 |  Coadd 
   72230 | 2024-03-21 13:33:07 |        MASTER-Tunka | (08h 44m 16.89s , +59d 00m 23.4s) |   C |    60 | 14.7 |  Coadd 
   72313 | 2024-03-21 13:34:30 |        MASTER-Tunka | (08h 49m 20.66s , +58d 52m 02.7s) |   C |    60 | 12.9 |  Coadd 
   80766 | 2024-03-21 15:55:48 |         MASTER-Amur | (09h 02m 06.67s , +67d 36m 52.7s) |   C |    10 | 15.8 |        
   80766 | 2024-03-21 15:55:48 |         MASTER-Amur | (09h 01m 59.37s , +67d 58m 27.7s) |   C |    10 | 16.1 |        
   80805 | 2024-03-21 15:56:27 |         MASTER-Amur | (09h 02m 06.57s , +67d 35m 07.2s) |   C |    10 | 15.8 |        
   80805 | 2024-03-21 15:56:27 |         MASTER-Amur | (09h 01m 59.52s , +67d 56m 43.7s) |   C |    10 | 16.0 |        
   80834 | 2024-03-21 15:56:56 |         MASTER-Amur | (08h 41m 37.71s , +67d 35m 50.6s) |   C |    10 | 15.8 |        
   80834 | 2024-03-21 15:56:56 |         MASTER-Amur | (08h 41m 31.44s , +67d 57m 26.9s) |   C |    10 | 16.0 |        
   80864 | 2024-03-21 15:57:26 |         MASTER-Amur | (08h 41m 32.86s , +67d 34m 59.8s) |   C |    10 | 15.7 |        
   80864 | 2024-03-21 15:57:26 |         MASTER-Amur | (08h 41m 26.59s , +67d 56m 42.7s) |   C |    10 | 15.9 |        
   80893 | 2024-03-21 15:57:55 |         MASTER-Amur | (08h 41m 33.39s , +67d 35m 44.6s) |   C |    10 | 15.8 |        
   80893 | 2024-03-21 15:57:55 |         MASTER-Amur | (08h 41m 27.16s , +67d 57m 27.9s) |   C |    10 | 15.9 |        
   80923 | 2024-03-21 15:58:25 |         MASTER-Amur | (08h 41m 39.41s , +67d 34m 30.6s) |   C |    10 | 15.8 |        
   80923 | 2024-03-21 15:58:25 |         MASTER-Amur | (08h 41m 33.20s , +67d 56m 14.3s) |   C |    10 | 16.1 |        
   80963 | 2024-03-21 15:58:55 |         MASTER-Amur | (08h 41m 33.61s , +67d 33m 14.3s) |   C |    30 | 16.3 |        
   80963 | 2024-03-21 15:58:55 |         MASTER-Amur | (08h 41m 27.54s , +67d 54m 59.0s) |   C |    30 | 16.6 |        
   81013 | 2024-03-21 15:59:45 |         MASTER-Amur | (08h 41m 40.23s , +67d 35m 41.2s) |   C |    30 | 15.4 |        
   81013 | 2024-03-21 15:59:45 |         MASTER-Amur | (08h 41m 34.15s , +67d 57m 26.4s) |   C |    30 | 15.7 |        
   81062 | 2024-03-21 16:00:34 |         MASTER-Amur | (08h 41m 37.02s , +67d 36m 44.4s) |   C |    30 | 15.8 |        
   81062 | 2024-03-21 16:00:34 |         MASTER-Amur | (08h 41m 30.97s , +67d 58m 30.1s) |   C |    30 | 16.3 |        
   81127 | 2024-03-21 16:01:24 |         MASTER-Amur | (08h 41m 37.50s , +67d 34m 57.2s) |   C |    60 | 15.5 |        
   81127 | 2024-03-21 16:01:24 |         MASTER-Amur | (08h 41m 31.42s , +67d 56m 43.6s) |   C |    60 | 16.0 |        
   81207 | 2024-03-21 16:02:44 |         MASTER-Amur | (08h 41m 42.72s , +67d 35m 45.5s) |   C |    60 | 15.5 |        
   81207 | 2024-03-21 16:02:44 |         MASTER-Amur | (08h 41m 36.68s , +67d 57m 33.0s) |   C |    60 | 16.0 |        
   81287 | 2024-03-21 16:04:05 |         MASTER-Amur | (08h 41m 37.54s , +67d 34m 19.1s) |   C |    60 | 15.5 |        
   81287 | 2024-03-21 16:04:05 |         MASTER-Amur | (08h 41m 32.01s , +67d 56m 06.4s) |   C |    60 | 15.8 |        
   82177 | 2024-03-21 16:18:54 |         MASTER-Amur | (08h 41m 37.32s , +67d 59m 35.7s) |   C |    60 | 17.3 |        
   82177 | 2024-03-21 16:18:54 |         MASTER-Amur | (08h 41m 47.95s , +67d 37m 53.7s) |   C |    60 | 16.6 |        
   82257 | 2024-03-21 16:20:14 |         MASTER-Amur | (08h 41m 43.13s , +67d 58m 37.2s) |   C |    60 | 17.2 |        
   82257 | 2024-03-21 16:20:14 |         MASTER-Amur | (08h 41m 53.19s , +67d 36m 50.6s) |   C |    60 | 16.6 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240318A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35974
SUBJECT: GRB 240318A: Fermi GBM Observation
DATE:    24/03/21 21:31:30 GMT
FROM:    Lorenzo Scotton at UAH <lscottongcn@outlook.com>

L. Scotton (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 02:51:01.82 UT on 18 March 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240318A (trigger 732423066/240318119),
which was also detected by Glowbug (Cheung et al. 2024, GCN 35959) 
and Swift/BAT-GUANO (DeLaunay et al. 2024, GCN 35969).
The Fermi GBM Final Real-time Localization was provided in GCN 35949. 

The angle from the Fermi LAT boresight is 53 degrees.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 8 s (50-300 keV). The time-averaged spectrum
from T0-2.0 to T0+11.0 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.5 +/- 0.2 and the cutoff energy,
parameterized as Epeak, is 112 +/- 8 keV.

The event fluence (10-1000 keV) in this time interval is
(2.1 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.1 s in the 10-1000 keV band is 4.5 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB240328B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35987
SUBJECT: GRB 240328B: Fermi GBM Final Real-time Localization
DATE:    24/03/28 19:19:46 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 19:09:10 UT on 28 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240328B (trigger 733345755.665982 / 240328798).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 223.4, Dec = -20.1 (J2000 degrees, equivalent to J2000 14h 53m, -20d 06'), with a statistical uncertainty of 11.6 degrees.

The angle from the Fermi LAT boresight is 78.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328798/quicklook/glg_skymap_all_bn240328798.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328798/quicklook/glg_healpix_all_bn240328798.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240328798/quicklook/glg_lc_medres34_bn240328798.gif


GRB_name: GRB240328C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35988
SUBJECT: GRB 240328C: Glowbug gamma-ray detection
DATE:    24/03/28 20:59:17 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240328C.

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-28 00:37:54.024 with a duration of 4.1 s and a total significance of about 16.9 sigma.  The light curve comprises a single peak.

Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a poorly constrained power-law index and a cutoff energy ("Epeak") of 213 keV.  The modeled 10-10000 keV fluence is 5.3e-07 erg/cm^2.

The best-fit localization is RA, Decl. (J2000, deg) = 165.0, 30.6 with a radius of 27.8 deg (95% confidence), with a highly uncertain systematic uncertainty.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240328A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35991
SUBJECT: Fermi GRB 240328A: Global MASTER-Net observations report
DATE:    24/03/29 17:30:52 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240328A ( Fermi GBM team, GCN 35986) errorbox  1 days 15952 sec after notice time and 1 days 15986 sec after trigger time at 2024-03-29 16:47:48 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 75 deg. The sun  altitude  is -35.1 deg. 

The galactic latitude b = 41 deg., longitude l =  0 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2409243

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

  102416 | 2024-03-29 16:47:48 |        MASTER-Tunka | (14h 43m 59.49s , -16d 29m 36.2s) |   C |    60 | 16.7 |        
  102417 | 2024-03-29 16:47:49 |        MASTER-Tunka | (14h 45m 17.79s , -15d 46m 24.1s) |   C |    60 | 17.5 |        
  102503 | 2024-03-29 16:49:15 |        MASTER-Tunka | (14h 59m 41.92s , -16d 31m 40.9s) |   C |    60 | 15.7 |        
  102504 | 2024-03-29 16:49:16 |        MASTER-Tunka | (15h 01m 00.09s , -15d 48m 28.9s) |   C |    60 | 16.2 |        
  102591 | 2024-03-29 16:50:43 |        MASTER-Tunka | (14h 51m 54.70s , -14d 36m 43.5s) |   C |    60 | 14.7 |        
  102625 | 2024-03-29 16:51:17 |        MASTER-Tunka | (14h 53m 11.85s , -13d 53m 33.8s) |   C |    60 | 15.4 |  Coadd 
  102705 | 2024-03-29 16:52:37 |        MASTER-Tunka | (15h 10m 06.13s , -17d 41m 11.5s) |   C |    60 | 14.3 |  Coadd 
  102838 | 2024-03-29 16:54:50 |        MASTER-Tunka | (15h 07m 35.00s , -14d 36m 19.1s) |   C |    60 | 15.5 |        
  102872 | 2024-03-29 16:55:24 |        MASTER-Tunka | (15h 08m 52.07s , -13d 53m 10.3s) |   C |    60 | 15.8 |  Coadd 
  104618 | 2024-03-29 17:24:30 |        MASTER-Tunka | (14h 43m 57.08s , -16d 28m 17.8s) |   C |    60 | 13.5 |        
  104666 | 2024-03-29 17:25:18 |        MASTER-Tunka | (14h 45m 14.95s , -15d 45m 08.6s) |   C |    60 | 14.5 |  Coadd 
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240328B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35992
SUBJECT: Fermi GRB 240328B: Global MASTER-Net observations report
DATE:    24/03/29 17:31:00 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240328B ( Fermi GBM team, GCN 35987) errorbox  77794 sec after notice time and 77830 sec after trigger time at 2024-03-29 16:46:21 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 77 deg. The sun  altitude  is -35.1 deg. 

The galactic latitude b = 34 deg., longitude l = 339 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2409475

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   77860 | 2024-03-29 16:46:21 |        MASTER-Tunka | (14h 36m 48.87s , -18d 22m 09.4s) |   C |    60 | 15.5 |        
   77861 | 2024-03-29 16:46:21 |        MASTER-Tunka | (14h 38m 08.41s , -17d 38m 54.4s) |   C |    60 | 17.1 |        
   77948 | 2024-03-29 16:47:48 |        MASTER-Tunka | (14h 43m 59.49s , -16d 29m 36.2s) |   C |    60 | 16.7 |        
   77949 | 2024-03-29 16:47:49 |        MASTER-Tunka | (14h 45m 17.79s , -15d 46m 24.1s) |   C |    60 | 17.5 |        
   78035 | 2024-03-29 16:49:15 |        MASTER-Tunka | (14h 59m 41.92s , -16d 31m 40.9s) |   C |    60 | 15.7 |        
   78036 | 2024-03-29 16:49:16 |        MASTER-Tunka | (15h 01m 00.09s , -15d 48m 28.9s) |   C |    60 | 16.2 |        
   78123 | 2024-03-29 16:50:43 |        MASTER-Tunka | (14h 51m 54.70s , -14d 36m 43.5s) |   C |    60 | 14.7 |        
   78157 | 2024-03-29 16:51:17 |        MASTER-Tunka | (14h 53m 11.85s , -13d 53m 33.8s) |   C |    60 | 15.4 |  Coadd 
   78237 | 2024-03-29 16:52:37 |        MASTER-Tunka | (15h 10m 06.13s , -17d 41m 11.5s) |   C |    60 | 14.3 |  Coadd 
   78286 | 2024-03-29 16:53:27 |        MASTER-Tunka | (14h 25m 09.56s , -22d 10m 42.9s) |   C |    60 | 15.8 |        
   78321 | 2024-03-29 16:54:01 |        MASTER-Tunka | (14h 26m 31.98s , -21d 27m 18.2s) |   C |    60 | 16.0 |  Coadd 
   78369 | 2024-03-29 16:54:50 |        MASTER-Tunka | (15h 07m 35.00s , -14d 36m 19.1s) |   C |    60 | 15.5 |        
   78404 | 2024-03-29 16:55:24 |        MASTER-Tunka | (15h 08m 52.07s , -13d 53m 10.3s) |   C |    60 | 15.8 |  Coadd 
   78450 | 2024-03-29 16:56:10 |        MASTER-Tunka | (14h 28m 06.63s , -16d 28m 01.7s) |   C |    60 | 16.8 |        
   78484 | 2024-03-29 16:56:45 |        MASTER-Tunka | (14h 29m 25.11s , -15d 44m 48.3s) |   C |    60 | 16.8 |  Coadd 
   80063 | 2024-03-29 17:23:03 |        MASTER-Tunka | (14h 36m 52.24s , -18d 20m 38.6s) |   C |    60 | 15.7 |        
   80150 | 2024-03-29 17:24:30 |        MASTER-Tunka | (14h 43m 57.08s , -16d 28m 17.8s) |   C |    60 | 13.5 |        
   80198 | 2024-03-29 17:25:18 |        MASTER-Tunka | (14h 45m 14.95s , -15d 45m 08.6s) |   C |    60 | 14.5 |  Coadd 
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240329A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35993
SUBJECT: GRB 240329A: Fermi GBM Final Real-time Localization
DATE:    24/03/29 21:53:41 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 21:43:07 UT on 29 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240329A (trigger 733441392.528372 / 240329905).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 259.7, Dec = -4.8 (J2000 degrees, equivalent to J2000 17h 18m, -4d 47'), with a statistical uncertainty of 3.8 degrees.

The angle from the Fermi LAT boresight is 97.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240329905/quicklook/glg_skymap_all_bn240329905.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240329905/quicklook/glg_healpix_all_bn240329905.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240329905/quicklook/glg_lc_medres34_bn240329905.gif


GRB_name: GRB240329A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35994
SUBJECT: GRB 240329A: BALROG localization (Fermi Trigger 733441392 / GRB 240329905)
DATE:    24/03/29 22:04:21 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
733441392 at 21:43:07 on 29 March 2024 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position is:
RA(2000.0) = 248.9 deg
Decl.(2000.0) = -1.4 deg
The 1 sigma statistical error radius is 3.4 deg.
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB240329905/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB240329905/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB240329905/json

                        


GRB_name: GRB240329A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  35995
SUBJECT: Fermi GRB 240329A: Global MASTER-Net observations report
DATE:    24/03/29 22:15:55 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240329A ( Fermi GBM team, GCN 35993) errorbox  567 sec after notice time and 601 sec after trigger time at 2024-03-29 21:53:08 UT, with upper limit up to  16.5 mag. The observations began at zenith distance = 81 deg. The sun  altitude  is -59.4 deg. 

The galactic latitude b = 18 deg., longitude l = 18 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2410319

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     631 | 2024-03-29 21:53:08 |         MASTER-SAAO | (17h 15m 08.53s , -04d 46m 28.6s) |   C |    60 | 16.5 |        
     711 | 2024-03-29 21:54:28 |         MASTER-SAAO | (17h 15m 09.18s , -04d 46m 22.7s) |   C |    60 | 16.3 |        
     790 | 2024-03-29 21:55:47 |         MASTER-SAAO | (17h 15m 09.74s , -04d 46m 17.5s) |   C |    60 | 16.2 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240331A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36000
SUBJECT: GRB 240331A: AstroSat CZTI detection
DATE:    24/04/01 10:25:36 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240331A which was also detected by the Fermi-GBM (Fermi-GBM Team, GCN Circ. 35998).

The source was clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-03-31 23:55:20.01 UTC. The measured peak count rate associated with the burst is 266 (+69, -53) counts/s above the background in the combined data of all quadrants, with a total of 1926 (+501, -548) counts. The local mean background count rate was 1448 (+8, -9) counts/s. We measure a T90 of 20 (+2, -6) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb 


GRB_name: GRB240324A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36001
SUBJECT: GRB 240324A: AstroSat CZTI detection of a short burst
DATE:    24/04/01 10:31:52 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>

J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a short-duration GRB 240324A. Inspection of INTEGRAL/SPI-ACS data also showed the detection of the burst.

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-03-24 03:35:14.25 UTC. The measured peak count rate associated with the burst is 365 (+162, -42) counts/s above the background in the combined data of all quadrants, with a total of 207 (+60, -59) counts. The local mean background count rate was 360 (+12, -14) counts/s. Using cumulative rates, we measure a T90 of 0.79 (+0.29, -0.27) s.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-03-24 03:35:13.39 UTC. The measured peak count rate associated with the burst is 660 (+79, -86) counts/s above the background in the combined data of all quadrants, with a total of 1191 (+246, -255) counts. The local mean background count rate was 1665 (+9, -10) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB240329A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36002
SUBJECT: GRB 240329A: Glowbug gamma-ray detection
DATE:    24/04/01 15:06:52 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240329A, which was also detected by Fermi/GBM (GCN 35993, 35994), GRBAlpha (GCN 35997), and AstroSat/CZTI (GCN 35999).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-29 21:43:05.936 with a duration of 7.1 s and a total significance of about 42 sigma. The light curve comprises two primary peaks at ~T0+1s and ~T0+4s, with a faint peak at ~T0+7s.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240402A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36012
SUBJECT: GRB 240402A: Fermi GBM Final Real-time Localization
DATE:    24/04/02 23:54:34 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 23:44:04 UT on 2 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240402A (trigger 733794249.222788 / 240402989).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 220.9, Dec = 29.3 (J2000 degrees, equivalent to J2000 14h 43m, 29d 18'), with a statistical uncertainty of 25.0 degrees.

The angle from the Fermi LAT boresight is 98.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240402989/quicklook/glg_skymap_all_bn240402989.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240402989/quicklook/glg_healpix_all_bn240402989.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240402989/quicklook/glg_lc_medres34_bn240402989.gif


GRB_name: GRB240402A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36013
SUBJECT: Fermi GRB 240402A: Global MASTER-Net observations report
DATE:    24/04/03 00:31:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 240402A ( Fermi GBM team, GCN 36012) errorbox  56 sec after notice time and 92 sec after trigger time at 2024-04-02 23:45:36 UT, with upper limit up to  19.8 mag. The observations began at zenith distance = 17 deg. The sun  altitude  is -30.8 deg. 

MASTER-SAAO robotic telescope  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240402A errorbox  283 sec after notice time and 318 sec after trigger time at 2024-04-02 23:49:23 UT, with upper limit up to  18.5 mag. The observations began at zenith distance = 78 deg. The sun  altitude  is -59.0 deg. 

The galactic latitude b = 65 deg., longitude l = 44 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2413376

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     182 | 2024-04-02 23:45:36 |   MASTER-Kislovodsk | (15h 12m 58.69s , +25d 58m 16.1s) |   C |   180 | 19.2 |        
     182 | 2024-04-02 23:45:36 |   MASTER-Kislovodsk | (15h 08m 03.72s , +26d 20m 19.6s) |   C |   180 | 19.8 |        
     330 | 2024-04-02 23:49:03 |   MASTER-Kislovodsk | (16h 13m 25.97s , +37d 31m 16.3s) |   C |    60 | 18.3 |        
     330 | 2024-04-02 23:49:03 |   MASTER-Kislovodsk | (16h 19m 02.25s , +37d 08m 45.3s) |   C |    60 | 19.1 |        
     349 | 2024-04-02 23:49:23 |         MASTER-SAAO | (16h 19m 55.22s , +38d 58m 47.5s) |   C |    60 | 16.1 |        
     421 | 2024-04-02 23:50:35 |   MASTER-Kislovodsk | (16h 14m 08.44s , +35d 13m 37.9s) |   C |    60 | 19.0 |        
     425 | 2024-04-02 23:50:39 |   MASTER-Kislovodsk | (16h 08m 40.42s , +35d 36m 13.1s) |   C |    60 | 18.1 |        
     443 | 2024-04-02 23:50:57 |         MASTER-SAAO | (16h 00m 22.97s , +39d 01m 30.8s) |   C |    60 | 17.7 |        
     505 | 2024-04-02 23:51:59 |   MASTER-Kislovodsk | (16h 27m 17.68s , +41d 17m 25.8s) |   C |    60 | 18.2 |        
     505 | 2024-04-02 23:51:59 |   MASTER-Kislovodsk | (16h 33m 11.34s , +40d 54m 41.2s) |   C |    60 | 19.1 |        
     535 | 2024-04-02 23:52:29 |         MASTER-SAAO | (15h 54m 33.78s , +37d 07m 14.2s) |   C |    60 | 17.8 |        
     585 | 2024-04-02 23:53:19 |   MASTER-Kislovodsk | (16h 27m 18.43s , +35d 35m 04.3s) |   C |    60 | 18.1 |        
     586 | 2024-04-02 23:53:19 |   MASTER-Kislovodsk | (16h 32m 45.73s , +35d 12m 25.9s) |   C |    60 | 18.9 |        
     628 | 2024-04-02 23:54:02 |         MASTER-SAAO | (16h 05m 06.50s , +33d 19m 48.0s) |   C |    60 | 17.9 |        
     666 | 2024-04-02 23:54:39 |   MASTER-Kislovodsk | (16h 15m 46.11s , +43d 13m 38.4s) |   C |    60 | 18.2 |        
     666 | 2024-04-02 23:54:39 |   MASTER-Kislovodsk | (16h 21m 50.67s , +42d 50m 47.1s) |   C |    60 | 19.0 |        
     720 | 2024-04-02 23:55:34 |         MASTER-SAAO | (15h 50m 12.26s , +35d 13m 34.4s) |   C |    60 | 17.9 |        
     746 | 2024-04-02 23:56:00 |   MASTER-Kislovodsk | (16h 23m 15.40s , +33d 41m 08.3s) |   C |    60 | 18.0 |        
     746 | 2024-04-02 23:56:00 |   MASTER-Kislovodsk | (16h 28m 35.35s , +33d 18m 27.6s) |   C |    60 | 19.0 |        
     815 | 2024-04-02 23:57:09 |         MASTER-SAAO | (15h 55m 25.17s , +42d 48m 09.2s) |   C |    60 | 15.9 |        
     826 | 2024-04-02 23:57:20 |   MASTER-Kislovodsk | (16h 36m 37.66s , +43d 13m 21.7s) |   C |    60 | 17.9 |        
     907 | 2024-04-02 23:58:40 |   MASTER-Kislovodsk | (15h 40m 20.30s , +39d 24m 34.9s) |   C |    60 | 18.3 |        
     907 | 2024-04-02 23:58:40 |   MASTER-Kislovodsk | (15h 46m 05.32s , +39d 01m 06.7s) |   C |    60 | 19.1 |        
     909 | 2024-04-02 23:58:43 |         MASTER-SAAO | (16h 02m 45.99s , +31d 24m 25.4s) |   C |    60 | 18.1 |        
     988 | 2024-04-03 00:00:02 |   MASTER-Kislovodsk | (16h 20m 24.70s , +31d 48m 55.2s) |   C |    60 | 18.1 |        
     988 | 2024-04-03 00:00:02 |   MASTER-Kislovodsk | (16h 25m 37.89s , +31d 25m 23.4s) |   C |    60 | 19.1 |        
    1001 | 2024-04-03 00:00:15 |         MASTER-SAAO | (15h 46m 56.79s , +33d 20m 42.9s) |   C |    60 | 18.1 |        
    1068 | 2024-04-03 00:01:22 |   MASTER-Kislovodsk | (16h 04m 35.13s , +45d 07m 13.7s) |   C |    60 | 18.0 |        
    1068 | 2024-04-03 00:01:22 |   MASTER-Kislovodsk | (16h 10m 52.08s , +44d 43m 13.8s) |   C |    60 | 19.0 |        
    1105 | 2024-04-03 00:01:59 |         MASTER-SAAO | (16h 46m 04.76s , +35d 10m 14.6s) |   C |    60 | 16.8 |        
    1149 | 2024-04-03 00:02:42 |   MASTER-Kislovodsk | (16h 41m 26.99s , +33d 40m 45.2s) |   C |    60 | 18.1 |        
    1149 | 2024-04-03 00:02:42 |   MASTER-Kislovodsk | (16h 46m 46.14s , +33d 17m 15.8s) |   C |    60 | 19.0 |        
    1201 | 2024-04-03 00:03:35 |         MASTER-SAAO | (15h 35m 39.18s , +37d 09m 08.1s) |   C |    60 | 17.9 |        
    1391 | 2024-04-03 00:06:45 |         MASTER-SAAO | (14h 53m 45.28s , +14d 23m 05.9s) |   C |    60 | 18.5 |        
    1493 | 2024-04-03 00:07:27 |   MASTER-Kislovodsk | (14h 58m 58.63s , +24d 04m 51.1s) |   C |   180 | 18.9 |        
    1493 | 2024-04-03 00:07:27 |   MASTER-Kislovodsk | (14h 54m 12.44s , +24d 27m 07.2s) |   C |   180 | 19.5 |        
    1488 | 2024-04-03 00:08:22 |         MASTER-SAAO | (16h 20m 04.04s , +39d 00m 18.3s) |   C |    60 | 16.8 |        
    1581 | 2024-04-03 00:09:55 |         MASTER-SAAO | (16h 00m 22.64s , +39d 00m 24.8s) |   C |    60 | 17.7 |        
    1640 | 2024-04-03 00:10:54 |   MASTER-Kislovodsk | (16h 13m 26.45s , +37d 29m 49.3s) |   C |    60 | 18.4 |        
    1640 | 2024-04-03 00:10:54 |   MASTER-Kislovodsk | (16h 19m 02.71s , +37d 07m 14.4s) |   C |    60 | 19.1 |        
    1673 | 2024-04-03 00:11:27 |         MASTER-SAAO | (15h 54m 43.06s , +37d 07m 09.0s) |   C |    60 | 18.0 |        
    1721 | 2024-04-03 00:12:14 |   MASTER-Kislovodsk | (16h 08m 38.80s , +35d 37m 20.6s) |   C |    60 | 18.1 |        
    1721 | 2024-04-03 00:12:14 |   MASTER-Kislovodsk | (16h 14m 06.47s , +35d 13m 52.5s) |   C |    60 | 19.0 |        
    1765 | 2024-04-03 00:12:59 |         MASTER-SAAO | (16h 05m 12.80s , +33d 20m 02.1s) |   C |    60 | 17.7 |        
    1801 | 2024-04-03 00:13:35 |   MASTER-Kislovodsk | (16h 27m 14.87s , +41d 18m 41.7s) |   C |    60 | 17.9 |        
    1801 | 2024-04-03 00:13:35 |   MASTER-Kislovodsk | (16h 33m 08.42s , +40d 54m 57.1s) |   C |    60 | 18.8 |        
    1857 | 2024-04-03 00:14:31 |         MASTER-SAAO | (15h 50m 14.26s , +35d 13m 11.9s) |   C |    60 | 17.7 |        
    1857 | 2024-04-03 00:14:31 |         MASTER-SAAO | (15h 48m 06.98s , +35d 26m 14.8s) |   C |    60 | 17.2 |        
    1881 | 2024-04-03 00:14:55 |   MASTER-Kislovodsk | (16h 27m 12.81s , +35d 37m 13.4s) |   C |    60 | 18.1 |        
    1881 | 2024-04-03 00:14:55 |   MASTER-Kislovodsk | (16h 32m 40.09s , +35d 13m 39.0s) |   C |    60 | 19.0 |        
    1937 | 2024-04-03 00:15:51 |         MASTER-SAAO | (15h 53m 16.83s , +43d 03m 43.3s) |   C |    60 | 16.0 |        
    1937 | 2024-04-03 00:15:51 |         MASTER-SAAO | (15h 55m 37.69s , +42d 50m 39.4s) |   C |    60 | 16.4 |        
    1968 | 2024-04-03 00:16:22 |   MASTER-Kislovodsk | (16h 15m 48.39s , +43d 12m 59.3s) |   C |    60 | 18.2 |        
    1968 | 2024-04-03 00:16:22 |   MASTER-Kislovodsk | (16h 21m 53.26s , +42d 49m 15.1s) |   C |    60 | 19.0 |        
    2016 | 2024-04-03 00:17:10 |         MASTER-SAAO | (16h 00m 41.87s , +31d 38m 28.9s) |   C |    60 | 17.4 |        
    2016 | 2024-04-03 00:17:10 |         MASTER-SAAO | (16h 02m 43.92s , +31d 25m 26.0s) |   C |    60 | 17.8 |        
    2048 | 2024-04-03 00:17:42 |   MASTER-Kislovodsk | (16h 23m 10.32s , +33d 41m 12.0s) |   C |    60 | 18.0 |        
    2048 | 2024-04-03 00:17:42 |   MASTER-Kislovodsk | (16h 28m 30.12s , +33d 17m 37.9s) |   C |    60 | 19.0 |        
    2096 | 2024-04-03 00:18:30 |         MASTER-SAAO | (15h 44m 53.33s , +33d 34m 17.4s) |   C |    60 | 17.4 |        
    2096 | 2024-04-03 00:18:30 |         MASTER-SAAO | (15h 46m 57.91s , +33d 21m 14.9s) |   C |    60 | 17.6 |        
    2128 | 2024-04-03 00:19:02 |   MASTER-Kislovodsk | (16h 36m 35.85s , +43d 12m 09.6s) |   C |    60 | 18.0 |        
    2176 | 2024-04-03 00:19:49 |         MASTER-SAAO | (16h 44m 02.30s , +35d 24m 23.6s) |   C |    60 | 16.1 |        
    2176 | 2024-04-03 00:19:49 |         MASTER-SAAO | (16h 46m 09.16s , +35d 11m 18.5s) |   C |    60 | 16.4 |        
    2212 | 2024-04-03 00:20:26 |   MASTER-Kislovodsk | (15h 42m 05.91s , +39d 17m 26.2s) |   C |    60 | 18.3 |        
    2212 | 2024-04-03 00:20:26 |   MASTER-Kislovodsk | (15h 36m 18.02s , +39d 39m 32.1s) |   C |    60 | 19.1 |        
    2255 | 2024-04-03 00:21:09 |         MASTER-SAAO | (15h 33m 24.47s , +37d 20m 59.2s) |   C |    60 | 17.2 |        
    2255 | 2024-04-03 00:21:09 |         MASTER-SAAO | (15h 35m 34.79s , +37d 07m 56.8s) |   C |    60 | 17.3 |        
    2298 | 2024-04-03 00:21:51 |   MASTER-Kislovodsk | (16h 25m 40.93s , +31d 23m 52.6s) |   C |    60 | 19.1 |        
    2298 | 2024-04-03 00:21:51 |   MASTER-Kislovodsk | (16h 20m 27.98s , +31d 47m 16.2s) |   C |    60 | 18.1 |        
    2335 | 2024-04-03 00:22:29 |         MASTER-SAAO | (16h 16m 59.52s , +29d 43m 12.7s) |   C |    60 | 17.4 |        
    2378 | 2024-04-03 00:23:12 |   MASTER-Kislovodsk | (16h 04m 34.59s , +45d 07m 57.2s) |   C |    60 | 18.1 |        
    2378 | 2024-04-03 00:23:12 |   MASTER-Kislovodsk | (16h 10m 51.11s , +44d 44m 45.0s) |   C |    60 | 18.9 |        
    2458 | 2024-04-03 00:24:32 |   MASTER-Kislovodsk | (16h 41m 25.01s , +33d 41m 59.4s) |   C |    60 | 18.1 |        
    2458 | 2024-04-03 00:24:32 |   MASTER-Kislovodsk | (16h 46m 44.92s , +33d 19m 30.3s) |   C |    60 | 19.0 |        
    2538 | 2024-04-03 00:25:52 |   MASTER-Kislovodsk | (16h 13m 23.00s , +37d 31m 10.7s) |   C |    60 | 18.3 |        
    2538 | 2024-04-03 00:25:52 |   MASTER-Kislovodsk | (16h 18m 58.79s , +37d 07m 57.4s) |   C |    60 | 19.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240402B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36017
SUBJECT: GRB 240402B: GECAM-C detection
DATE:    24/04/03 17:01:02 GMT
FROM:    Kai <wcxuemail@gmail.com>

Wang-Chen Xue, Shao-Lin Xiong, Chao Zheng, Yanqiu Zhang, and Chengkui Li,
report on behalf of the GECAM team:

GECAM-C observed a long burst, GRB 240402B at
2024-04-02T08:47:46 UTC (denoted as T0), which has been 
detected by LEIA (GCN 36016) and Konus-Wind.

According to the observation data of GECAM-C, this burst mainly consists
of two peaks with a duration (T90) of 6.55 +/- 0.52 sec (15-350 keV).

The GECAM-C localization is consistent with the LEIA localization
(GCN 36016) within the error.

The time-averaged spectrum of GECAM-C data from T0-7.0 to T0+7.0 s could be
adequately fit by a cut-off power-law with photon index alpha of -0.62 (-0.14, +0.13),
and peak energy Ep of 66 (-3, +3) keV. The corresponding burst fluence is
7.69 (-0.24, +0.25) * 10^-7 erg/cm^2 in 15-350 keV.

We note that these results are preliminary and refined analysis will be reported later.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B)
launched in Dec. 2020. As the third member of GECAM constellation, 
GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. 
GECAM mission is funded by the Chinese Academy of Sciences (CAS).


GRB_name: GRB240402B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36018
SUBJECT: GRB 240402B: GWAC-F50A optical upper limit
DATE:    24/04/03 22:56:22 GMT
FROM:    Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>


L.P.Xin(NAOC), Y.G.Yang(HNU), C.WU(NAOC), Y.L.Qiu(NAOC), J.Wang(GXU/NAOC),  
L.H.Li(NAOC),  C.Wu(NAOC),  E.W.Liang(GXU), X.H.Han (NAOC), X.M.Lu(NAOC), 
R.S.Zhang(NAOC), Y.Xu(NAOC), Y.J.Xiao(NAOC), P.P.Zhang(NAOC), L.Lan(NAOC), 
J.Y.Wei(NAOC) on behalf of the SVOM/GWAC team:

We began to observe X-ray transient LXT 240402A (Xu et all., GCN 36106) detected by LEIA,
which was also detected by GECAME-C as GRB 240402B (Xue et al., GCN 36107),
with GWAC-F50A telescope, at Xinglong station, China, at 19:22:13 (UT), 03. April. 2024,  
about 34.57 hours after the burst. The weather was not good.

After stacking 5*200 seconds, no any new sources were detected in our stacked image 
down to a limit magnitude of 18.0 mag in R band comparing to several nearby USNO B1.0 stars.

We acknowledge the excellent support from observation assistant Yangtong Zheng. 


GRB_name: GRB240404A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36020
SUBJECT: GRB 240404A: Fermi GBM Final Real-time Localization
DATE:    24/04/04 02:46:02 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 02:38:04 UT on 4 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240404A (trigger 733891089.631386 / 240404110).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 257.0, Dec = -27.3 (J2000 degrees, equivalent to J2000 17h 07m, -27d 18'), with a statistical uncertainty of 13.3 degrees.

The angle from the Fermi LAT boresight is 93.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240404110/quicklook/glg_skymap_all_bn240404110.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240404110/quicklook/glg_healpix_all_bn240404110.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240404110/quicklook/glg_lc_medres34_bn240404110.gif


GRB_name: GRB240404A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36021
SUBJECT: Fermi GRB 240404A: Global MASTER-Net observations report
DATE:    24/04/04 03:16:11 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240404A ( Fermi GBM team, GCN 36020) errorbox  1191 sec after notice time and 1229 sec after trigger time at 2024-04-04 02:58:34 UT, with upper limit up to  18.5 mag. The observations began at zenith distance = 10 deg. The sun  altitude  is -24.8 deg. 

The galactic latitude b =  7 deg., longitude l = 357 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2414151

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    1260 | 2024-04-04 02:58:34 |         MASTER-SAAO | (16h 31m 03.20s , -27d 28m 14.7s) |   C |    60 | 18.5 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240403A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36024
SUBJECT: GRB 240403A: Fermi GBM Detection
DATE:    24/04/04 14:27:05 GMT
FROM:    rachel.hamburg@ijclab.in2p3.fr

R. Hamburg (CNRS/IN2P3/IJCLab), S. Dalessi (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 11:57:30.58 UT on 03 April 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240403A (trigger 733838255/240403498).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 6.5, Dec = -17.3 (J2000 degrees, equivalent to
J2000 +00h 26m, -17d 17'), with a statistical uncertainty of 1.77 degrees.
There is additionally a systematic error which we have characterized 
as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a
small tail suffering a larger than 10 deg systematic error (Connaughton 
et al. 2015, ApJS, 216, 32).

The angle from the Fermi LAT boresight is 62 degrees.

The GBM light curve shows a precursor, a main emission peak 
and third weaker peak, yielding a duration (T90)
of about 35.6 s (50-300 keV). The time-averaged spectrum
from T0-1.2 to T0+76.7 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.11 +/- 0.01 and the cutoff energy,
parameterized as Epeak, is 350 +/- 10 keV. 
A Band function also fits well with Epeak = 322 +/- 14 keV,
alpha = -1.08 +/- 0.02, and beta = -2.40 +/- 0.13.

The event fluence (10-1000 keV) in this time interval is
(3.6 +/- 0.4)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+26 s in the 10-1000 keV band is 39.1 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB240402B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36025
SUBJECT: GRB/FXT 240402B: VLT/FORS2 optical afterglow candidate
DATE:    24/04/04 14:40:14 GMT
FROM:    Andrew Levan at Radboud University <a.levan@astro.ru.nl>

A.J. Levan (Radboud), D.B. Malesani (DAWN/NBI & Radboud), P.G. Jonker (Radboud), N.R. Tanvir (Leicester), M. E. Ravasio (Radboud), A. Martin-Carrillo (UCD), G. Pugliese (Amsterdam), S. Campana (INAF/Brera), D. Xu (NAOC/CAS) report on behalf of the Stargate collaboration: 

We obtained observations of FXT/GRB 240402B (Xu et al., GCN 36016; Xue et al., GCN 36017) with the FORS2 imager on the VLT UT1 (Antu). Observations began at 06:44 UT on 4 April 2024, approximately 1.9 days after the high-energy detection. We obtained a total of 1400 s of observations in the R band. Within the 10â€ error box of the X-ray transient located by Einstein Probe follow-up observations (Jia et al., GCN 36022), we identify a new source not present in archival images retrieved via the Legacy Survey. This source lies at 

RA = 16:21:48.247
Dec = +25:45:47.34

We suggest this is the optical afterglow of FXT/GRB240402B. Photometry is complicated by the presence of a nearby star just 1â€ away (a confirmed star, given a Gaia measured proper motion), but the magnitude of the transient at the time of the observations was approximately r ~ 22 calibrated to Pan-STARRS. The offset from the nearby galaxy CGCG 138-001 (z = 0.047) is approximately 200 kpc in projection, at the higher end of those expected for ejected compact object mergers.

We thank the staff at the VLT for the rapid execution of these observations, in particular Julia Seidel.


GRB_name: GRB240402A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36027
SUBJECT: GRB/FXT 240402B: Kinder optical counterpart candidate
DATE:    24/04/04 15:37:12 GMT
FROM:    Janet Chen at National Central University <janetstars@gmail.com>

S. Yang (HNAS), T.-W. Chen, H.-Y. Hsiao, W.-J. Hou, A. Sankar.K, Y.-C. Pan, M.-H. Lee, C.-H. Lai, C.-C. Ngeow, C.-S. Lin, H.-C. Lin, J.-K. Guo (all NCUIA), S. J. Smartt,  J. Gillanders, L. Rhodes, S. Srivastav (all Oxford) and T. Moore (QUB) report:

Following the detection of an X-ray transient (LXT 240402A) by LEIA (Xu et al. GCN 36016) and FXT on board â€‹Einstein Probe (Jia et al. GCN 36022), and an associated GRB 240402A by GECAM-C (Xue et al. GCN 36017), we used several telescopes at the Lulin Observatory, Taiwan as part of the Kinder collaboration (Chen et al., AstroNote 2021-92) for optical counterpart searches. Our followup facilities includes the Lulin One-meter Telescope (LOT) with g and r bands, and the 40cm Super Light Telescope (SLT) with r and i bands, and our observing details were below:

Telescope | Filter | MJD | t-t0 | Explosure | avg. Seeing | med. Airmass
SLT | r | 60403.644 | 1.28 day | 300 sec * 15 | 1".8 | 1.33 
SLT | i | 60403.713 | 1.35 day | 300 sec * 44 | 1".8 | 1.03 
LOT | r | 60403.720 | 1.35 day | 300 sec * 12 | 1".2 | 1.08
LOT | g | 60403.771 | 1.40 day | 300 sec * 10 | 1".2 | 1.04 

(1). LXT 240402A

We used the Kinder pipeline (Yang et al. A&A 646, A22) to stack the images with same pointing and subtract the stacked images with the LEGACY SURVEY template images. We do not detect significant optical counterpart candidates within the 1.5 arcmin error area of LXT 240402A. In 2.5 sigma level, we obtained the following preliminary upper limits (in the AB system): 

SLT r > 22.74, 
SLT i > 22.61, 
LOT r > 23.57 and 
LOT g >  23.58 mag.

Our result is consistent with GWAC-F50A (Xin et al., GCN 36018), MASTER (Lipunov et al., GCN 36019) and AST3-3 (Sun et al., GCN 36023), and our limits are deeper than these reports.

(2). FXT/GRB 240402B 

Furthermore, we noticed that EP-FXT announced the detection of the X-ray afterglow (Jia et al., GCN 36022) of LXT240402A, which is 2.4 arcmin away from the LEIA source. We thus repeat the procedure detailed above on this specific position and found a clear optical counterpart at the location of RA = 16:21:48.225, Dec = 25:45:47.57 in the differencing images. We measured the PSF magnitudes of this source after subtracted with the LEGACY SURVEY templates and obtained (all in the AB system):

g = 22.86 +/- 0.09 and
r =  22.28 +/-  0.10 mag.
No deep i-band template images were available in the LEGACY SURVEY archive, so we do not report the measurements in this note. Further analysis is on-going.

The given magnitudes are derived based on calibrating against SDSS field stars and is not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.03 mag in the direction of the burst (Schlafly & Finkbeiner 2011).

We note that this source is difficult to resolve from a star (i.e. SDSS J162148.18+254546.5, r = 20.6 mag) in our images. Upon visual inspection, the star appears to have a broader profile.

We independently identified this optical counterpart candidate while drafting this report, and we noticed that this counterpart has also been reported in Levan et al., GCN 36025.

We thank the Einstein Probe team for useful communication.


GRB_name: GRB240402B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36028
SUBJECT: Konus-Wind detection of LXT 240402A/GRB 240402B
DATE:    24/04/04 15:59:11 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 240402B 
(GECAM-C detection: Xue et al., GCN 36017)
associated with the LEIA fast X-ray transient 
LXT 240402A (Xu et al., GCN 36016)
triggered Konus-Wind at T0=31668.797 s UT (08:47:48.797).

The burst light curve shows a multipeaked structure
which starts at ~T0-0.2 s and has a total duration of ~5.1 s.
The emission is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240402_T31668/

As observed by Konus-Wind, the burst
had a fluence of 7.56(-0.43,+0.50)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+2.704 s,
of 5.07(-0.66,+0.68)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 4 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.71(-0.17,+0.19),
the high energy photon index beta = -3.58(-1.30,+0.44),
the peak energy Ep = 86(-4,+5) keV
(chi2 = 57/68 dof).

This spectrum is nearly-well fitted 
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.78(-0.15,+0.16)
and Ep = 88(-4,+4) keV (chi2 = 61/69 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB240402B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36030
SUBJECT: LXT 240402A/GRB 240402B: Glowbug gamma-ray detection
DATE:    24/04/04 19:13:46 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of LXT 240402A/GRB 240402B, which was also detected by LEIA (GCN 36016), GECAM-C (GCN 36017), and Konus/Wind (GCN 36028).
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-02 08:47:45.240 with a duration of 4.1 s and a total significance of about 18.3 sigma.  The light curve comprises two primary peaks at ~T0+0.5s and ~T0+3s.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240403A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36031
SUBJECT: GRB 240403A: Glowbug gamma-ray detection
DATE:    24/04/04 21:35:35 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240403A, which was also detected by Fermi/GBM (GCN 36015, 36024). 

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-03 11:57:53.912 with a duration of 7.2 s and a total significance of about 31.9 sigma. The Glowbug onset corresponds to the main emission peak seen in the GBM light curve (GCN 36024).

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240403B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36032
SUBJECT: GRB 240403B: Glowbug gamma-ray detection
DATE:    24/04/04 21:36:45 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240403B, which was also detected by Fermi/GBM (Trigger 733808041). 

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-03 03:33:50.176 with a duration of 26.6 s and a total significance of about 57 sigma.  The light curve shows a gradual increase in flux (uncertain between ~T0+20s to ~T0+23s because of detector dead-time) with a sharp peak at ~T0+25s.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240402B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36034
SUBJECT: LXT 240402A/GRB 240402B: GECAM-C refined analysis
DATE:    24/04/05 01:59:44 GMT
FROM:    Chenwei Wang at IHEP <cwwang@ihep.ac.cn>

Wangchen Xue, Shaolin Xiong, Chenwei Wang, Chengkui Li, Shuxu Yi on behalf of GECAM team

Following our initial analysis reported in GCN 36017, here we analyzed the Amati relation for this burst. 
We find that, if this burst had a redshift of z~0.047 (Levan et al.; GCN 36025, Xu et al., GCN 36016), 
it falls in the short burst region, supporting the compact object merger origin as also evident by the large offset from the galaxy (Levan et al., GCN 36025). 
 
The small spectral lag compared to its luminosity also indicates the compact object merger origin.

The associated gravitational wave would likely have been observed if LVK was observing at the time of this burst.
The gravitational wave of such kind of GRB with small redshift would be potentially observed in O4b of LVK.

With the probable compact object merger origin of this GRB, follow-up observations are encouraged.


GRB_name: GRB240402C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36036
SUBJECT: GRB 240402C: GRBAlpha detection
DATE:    24/04/05 14:27:47 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The long-duration GRB 240402C (CALET/CGBM detection: trigger no. 1396070722; INTEGRAL/SPI-ACS peak detection at 2024-04-02 ~05:29:48 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract).

The detection was confirmed at the peak time 2024-04-02 05:30:53.0 UTC. The T90 duration measured by GRBAlpha is 91.0 s and the overall significance during T90 reaches 11 sigma in the 120-400 keV band.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240402C_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. 


GRB_name: GRB240405A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36037
SUBJECT: GRB 240405A: Fermi GBM Final Real-time Localization
DATE:    24/04/05 15:17:52 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 15:06:46 UT on 5 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240405A (trigger 734022411.49845 / 240405630).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 289.6, Dec = 37.8 (J2000 degrees, equivalent to J2000 19h 18m, 37d 47'), with a statistical uncertainty of 5.2 degrees.

The angle from the Fermi LAT boresight is 143.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240405630/quicklook/glg_skymap_all_bn240405630.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240405630/quicklook/glg_healpix_all_bn240405630.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240405630/quicklook/glg_lc_medres34_bn240405630.gif


GRB_name: GRB240402C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36038
SUBJECT: GRB 240402C: Glowbug gamma-ray detection
DATE:    24/04/05 17:03:54 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240402C, which was also detected by GRBAlpha (GCN 36036), INTEGRAL/SPI-ACS, and CALET/CGBM (Trigger 1396070722). 

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-02 05:29:43.544 with a duration of 98.3 s and a total significance of about 16 sigma.  The light curve comprises an initial double-peaked structure from T0 to T0+20s, and a complex multi-peaked structure from T0+60s to T0+80s.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240405B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36039
SUBJECT: GRB 240405B: Fermi GBM Final Real-time Localization
DATE:    24/04/05 22:32:47 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 22:22:27 UT on 5 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240405B (trigger 734048552.443682 / 240405932).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 262.8, Dec = 44.8 (J2000 degrees, equivalent to J2000 17h 31m, 44d 47'), with a statistical uncertainty of 8.7 degrees.

The angle from the Fermi LAT boresight is 55.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240405932/quicklook/glg_skymap_all_bn240405932.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240405932/quicklook/glg_healpix_all_bn240405932.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240405932/quicklook/glg_lc_medres34_bn240405932.gif


GRB_name: GRB240405B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36040
SUBJECT: Fermi GRB 240405B: Global MASTER-Net observations report
DATE:    24/04/05 23:16:14 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240405B ( Fermi GBM team, GCN 36039) errorbox  1885 sec after notice time and 1920 sec after trigger time at 2024-04-05 22:54:27 UT, with upper limit up to  19.4 mag. The observations began at zenith distance = 34 deg. The sun  altitude  is -37.2 deg. 

The galactic latitude b = 32 deg., longitude l = 71 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2415539

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    1950 | 2024-04-05 22:54:27 |      MASTER-Tavrida | (17h 22m 31.42s , +45d 05m 50.3s) |   C |    60 | 19.2 |        
    2101 | 2024-04-05 22:56:58 |      MASTER-Tavrida | (17h 31m 17.62s , +43d 11m 34.5s) |   C |    60 | 19.0 |        
    2253 | 2024-04-05 22:59:30 |      MASTER-Tavrida | (17h 10m 24.70s , +43d 14m 19.7s) |   C |    60 | 19.1 |        
    2414 | 2024-04-05 23:02:11 |      MASTER-Tavrida | (17h 14m 28.16s , +47d 00m 34.6s) |   C |    60 | 19.3 |        
    2640 | 2024-04-05 23:05:57 |      MASTER-Tavrida | (17h 36m 34.61s , +47d 00m 21.4s) |   C |    60 | 19.2 |        
    2795 | 2024-04-05 23:08:32 |      MASTER-Tavrida | (17h 20m 20.88s , +41d 18m 01.9s) |   C |    60 | 19.4 |        
    2867 | 2024-04-05 23:09:44 |      MASTER-Tavrida | (17h 22m 34.70s , +45d 06m 27.5s) |   C |    60 | 19.3 |        
    2939 | 2024-04-05 23:10:56 |      MASTER-Tavrida | (17h 33m 51.42s , +45d 07m 19.3s) |   C |    60 | 19.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240407A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36044
SUBJECT: GRB 240407A: Fermi GBM Final Real-time Localization
DATE:    24/04/07 01:10:24 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 00:59:51 UT on 7 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240407A (trigger 734144396.810938 / 240407042).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 352.3, Dec = 44.9 (J2000 degrees, equivalent to J2000 23h 29m, 44d 53'), with a statistical uncertainty of 1.7 degrees.

The angle from the Fermi LAT boresight is 88.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240407042/quicklook/glg_skymap_all_bn240407042.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240407042/quicklook/glg_healpix_all_bn240407042.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240407042/quicklook/glg_lc_medres34_bn240407042.gif


GRB_name: GRB240407A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36045
SUBJECT: Fermi GRB 240407A: Global MASTER-Net observations report
DATE:    24/04/07 02:45:42 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 240407A ( Fermi GBM team, GCN 36044) errorbox  26 sec after notice time and 73 sec after trigger time at 2024-04-07 01:01:05 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 66 deg. The sun  altitude  is -18.3 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240407A errorbox  96 sec after notice time and 144 sec after trigger time at 2024-04-07 01:02:16 UT, with upper limit up to  19.1 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -22.5 deg. 

The galactic latitude b = -15 deg., longitude l = 109 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2416508

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

      79 | 2024-04-07 01:01:05 |   MASTER-Kislovodsk | (23h 32m 39.83s , +47d 04m 24.7s) |   C |    10 | 15.1 |        
      79 | 2024-04-07 01:01:05 |   MASTER-Kislovodsk | (23h 38m 18.06s , +46d 40m 40.3s) |   C |    10 | 16.3 |        
     109 | 2024-04-07 01:01:05 |   MASTER-Kislovodsk | (23h 38m 18.06s , +46d 40m 40.2s) |   C |    70 | 17.5 |  Coadd 
     114 | 2024-04-07 01:01:36 |   MASTER-Kislovodsk | (23h 38m 15.40s , +46d 42m 04.5s) |   C |    20 | 16.7 |        
     115 | 2024-04-07 01:01:36 |   MASTER-Kislovodsk | (23h 32m 37.08s , +47d 05m 49.7s) |   C |    20 | 15.5 |        
     140 | 2024-04-07 01:01:36 |   MASTER-Kislovodsk | (23h 32m 37.08s , +47d 05m 49.7s) |   C |    70 | 16.0 |  Coadd 
     159 | 2024-04-07 01:02:16 |      MASTER-Tavrida | (23h 35m 26.07s , +47d 13m 42.4s) |   C |    30 | 17.7 |        
     166 | 2024-04-07 01:02:22 |   MASTER-Kislovodsk | (23h 34m 12.10s , +44d 47m 19.9s) |  P| |    30 | 16.3 |        
     205 | 2024-04-07 01:02:56 |      MASTER-Tavrida | (23h 25m 50.18s , +44d 56m 12.4s) |   C |    40 | 18.2 |        
     221 | 2024-04-07 01:03:13 |   MASTER-Kislovodsk | (23h 38m 21.46s , +46d 42m 31.3s) |   C |    40 | 17.2 |        
     221 | 2024-04-07 01:03:13 |   MASTER-Kislovodsk | (23h 32m 42.10s , +47d 06m 14.2s) |   C |    40 | 15.6 |        
     287 | 2024-04-07 01:04:13 |   MASTER-Kislovodsk | (23h 38m 15.32s , +46d 41m 33.6s) |   C |    50 | 17.2 |        
     287 | 2024-04-07 01:04:13 |   MASTER-Kislovodsk | (23h 32m 36.04s , +47d 05m 16.4s) |   C |    50 | 15.6 |        
     363 | 2024-04-07 01:05:25 |   MASTER-Kislovodsk | (23h 38m 15.55s , +46d 42m 33.8s) |   C |    60 | 17.4 |        
     363 | 2024-04-07 01:05:25 |   MASTER-Kislovodsk | (23h 32m 36.12s , +47d 06m 17.0s) |   C |    60 | 16.0 |        
     821 | 2024-04-07 01:12:17 |      MASTER-Tavrida | (23h 25m 56.16s , +44d 55m 51.6s) |   C |   150 | 19.1 |        
    1580 | 2024-04-07 01:25:41 |   MASTER-Kislovodsk | (23h 35m 57.51s , +44d 57m 58.9s) |   C |    60 | 16.1 |        
    1580 | 2024-04-07 01:25:41 |   MASTER-Kislovodsk | (23h 41m 24.62s , +44d 33m 59.5s) |   C |    60 | 17.2 |        
    1660 | 2024-04-07 01:27:01 |   MASTER-Kislovodsk | (23h 32m 48.85s , +43d 03m 11.1s) |   C |    60 | 15.9 |        
    1660 | 2024-04-07 01:27:01 |   MASTER-Kislovodsk | (23h 38m 05.44s , +42d 39m 11.0s) |   C |    60 | 17.0 |        
    1741 | 2024-04-07 01:28:22 |   MASTER-Kislovodsk | (23h 18m 29.88s , +46d 52m 36.1s) |   C |    60 | 16.2 |        
    1741 | 2024-04-07 01:28:22 |   MASTER-Kislovodsk | (23h 24m 09.97s , +46d 28m 38.3s) |   C |    60 | 17.2 |        
    1821 | 2024-04-07 01:29:42 |   MASTER-Kislovodsk | (23h 14m 29.30s , +44d 57m 47.8s) |   C |    60 | 16.0 |        
    1821 | 2024-04-07 01:29:42 |   MASTER-Kislovodsk | (23h 19m 57.98s , +44d 33m 52.2s) |   C |    60 | 17.2 |        
    1901 | 2024-04-07 01:31:02 |   MASTER-Kislovodsk | (23h 40m 42.22s , +46d 49m 58.8s) |   C |    60 | 15.7 |        
    1901 | 2024-04-07 01:31:02 |   MASTER-Kislovodsk | (23h 46m 20.74s , +46d 25m 54.7s) |   C |    60 | 16.8 |        
    1981 | 2024-04-07 01:32:23 |   MASTER-Kislovodsk | (23h 12m 09.93s , +43d 03m 11.9s) |   C |    60 | 15.9 |        
    1981 | 2024-04-07 01:32:23 |   MASTER-Kislovodsk | (23h 17m 28.24s , +42d 39m 17.9s) |   C |    60 | 17.0 |        
    2062 | 2024-04-07 01:33:43 |   MASTER-Kislovodsk | (23h 30m 24.58s , +48d 22m 17.6s) |   C |    60 | 16.5 |        
    2463 | 2024-04-07 01:40:24 |   MASTER-Kislovodsk | (23h 35m 56.74s , +44d 57m 25.5s) |   C |    60 | 15.1 |        
    2463 | 2024-04-07 01:40:24 |   MASTER-Kislovodsk | (23h 41m 24.46s , +44d 33m 25.3s) |   C |    60 | 16.2 |        
    2623 | 2024-04-07 01:43:04 |   MASTER-Kislovodsk | (23h 32m 55.39s , +43d 02m 46.5s) |   C |    60 | 15.0 |        
    2623 | 2024-04-07 01:43:04 |   MASTER-Kislovodsk | (23h 38m 12.58s , +42d 38m 48.4s) |   C |    60 | 16.0 |        
    2703 | 2024-04-07 01:44:25 |   MASTER-Kislovodsk | (23h 18m 31.66s , +46d 52m 37.3s) |   C |    60 | 14.9 |        
    2703 | 2024-04-07 01:44:25 |   MASTER-Kislovodsk | (23h 24m 12.78s , +46d 28m 40.9s) |   C |    60 | 16.0 |        
    2784 | 2024-04-07 01:45:45 |   MASTER-Kislovodsk | (23h 14m 27.19s , +44d 57m 14.5s) |   C |    60 | 14.1 |        
    2784 | 2024-04-07 01:45:45 |   MASTER-Kislovodsk | (23h 19m 55.94s , +44d 33m 21.2s) |   C |    60 | 15.9 |        
    2864 | 2024-04-07 01:47:05 |   MASTER-Kislovodsk | (23h 46m 27.01s , +46d 28m 03.3s) |   C |    60 | 15.5 |        
    2944 | 2024-04-07 01:48:25 |   MASTER-Kislovodsk | (23h 17m 21.90s , +42d 40m 35.5s) |   C |    60 | 15.5 |        
    3024 | 2024-04-07 01:49:46 |   MASTER-Kislovodsk | (23h 30m 22.68s , +48d 23m 01.0s) |   C |    60 | 15.2 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240402C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36046
SUBJECT: GRB 240402C: CALET Gamma-Ray Burst Monitor detection
DATE:    24/04/07 08:07:31 GMT
FROM:    Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>

Y. Asaoka (ICRR), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA), S. Torii, Y. Akaike, 
K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 240402C (GRBAlpha detection: Dafcikova et al., GCN Circ. 36036;
Glowbug gamma-ray detection: Cheung et al., GCN Circ. 36038) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 05:30:42.49 UTC on 2 April 2024
(http://cgbm.calet.jp/cgbm_trigger/flight/1396070722/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a double-peaked structure that starts
at T-62.6 sec, peaks at T+1.6 sec, and ends at T+21.1 sec.
The T90 and T50 durations measured by the SGM data are 76.5 +/- 2.6 sec
and 53.5 +/- 1.0 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1396070722/index.html

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB240408A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36048
SUBJECT: GRB 240408A: Fermi GBM Final Real-time Localization
DATE:    24/04/08 01:12:52 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 01:02:12 UT on 8 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240408A (trigger 734230937.764604 / 240408043).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 353.5, Dec = 50.1 (J2000 degrees, equivalent to J2000 23h 33m, 50d 06'), with a statistical uncertainty of 13.4 degrees.

The angle from the Fermi LAT boresight is 32.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240408043/quicklook/glg_skymap_all_bn240408043.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240408043/quicklook/glg_healpix_all_bn240408043.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240408043/quicklook/glg_lc_medres34_bn240408043.gif


GRB_name: GRB240408A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36049
SUBJECT: Fermi GRB 240408A: Global MASTER-Net observations report
DATE:    24/04/08 01:16:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240408A ( Fermi GBM team, GCN 36048) errorbox  22 sec after notice time and 61 sec after trigger time at 2024-04-08 01:03:14 UT, with upper limit up to  17.9 mag. The observations began at zenith distance = 70 deg. The sun  altitude  is -22.0 deg. 

The galactic latitude b = -11 deg., longitude l = 111 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2417230

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

      92 | 2024-04-08 01:03:14 |      MASTER-Tavrida | (23h 13m 54.05s , +41d 05m 54.4s) |   C |    60 | 17.9 |        
     165 | 2024-04-08 01:04:27 |      MASTER-Tavrida | (23h 45m 13.46s , +43d 00m 24.3s) |   C |    60 | 17.7 |        
     237 | 2024-04-08 01:05:39 |      MASTER-Tavrida | (23h 56m 08.75s , +42d 58m 55.2s) |   C |    60 | 17.5 |        
     308 | 2024-04-08 01:06:50 |      MASTER-Tavrida | (23h 50m 56.56s , +44d 54m 25.3s) |   C |    60 | 17.7 |        
     380 | 2024-04-08 01:08:02 |      MASTER-Tavrida | (00h 02m 06.98s , +44d 53m 31.2s) |   C |    60 | 17.6 |        
     452 | 2024-04-08 01:09:14 |      MASTER-Tavrida | (23h 48m 34.73s , +44d 54m 50.7s) |   C |    60 | 17.7 |        
     524 | 2024-04-08 01:10:26 |      MASTER-Tavrida | (23h 59m 57.61s , +44d 53m 36.5s) |   C |    60 | 17.6 |        
     598 | 2024-04-08 01:11:40 |      MASTER-Tavrida | (23h 23m 48.44s , +39d 11m 37.5s) |   C |    60 | 17.9 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240405A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36054
SUBJECT: GRB 240405A: GRBAlpha detection
DATE:    24/04/09 15:51:10 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The long-duration GRB 240405A (Fermi/GBM detection: GCN 36037) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract).

The detection was confirmed at the peak time 2024-04-05 15:07:38.5 UTC. The T90 duration measured by GRBAlpha is 24.0 s and the overall significance during T90 reaches 7 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240405A_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. 


GRB_name: GRB240411A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36061
SUBJECT: GRB 240411A: Fermi GBM Final Real-time Localization
DATE:    24/04/11 01:55:28 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 01:44:58 UT on 11 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240411A (trigger 734492703.48149 / 240411073).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 242.6, Dec = 40.6 (J2000 degrees, equivalent to J2000 16h 10m, 40d 36'), with a statistical uncertainty of 5.4 degrees.

The angle from the Fermi LAT boresight is 64.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240411073/quicklook/glg_skymap_all_bn240411073.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240411073/quicklook/glg_healpix_all_bn240411073.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240411073/quicklook/glg_lc_medres34_bn240411073.gif


GRB_name: GRB240411B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36063
SUBJECT: GRB 240411B: Swift detection of a burst
DATE:    24/04/11 16:09:02 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


T. M. Parsotan (GSFC), S. Dichiara (PSU),
R. A. J. Eyles-Ferris (U Leicester), C. Gronwall (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), K. L. Page (U Leicester),
B. Sbarufatti (INAF-OAB), M. H. Siegel (PSU) and M. A. Williams (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 15:32:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240411B (trigger=1221183).  Swift slewed immediately to the burst. 
No further BAT information is available at this time due to a
telemetry gap.  Further information will be available after the
next telemetry pass over a ground station. 

The XRT began observing the field at approximately 15:35:54 UT, around 180
seconds after the BAT trigger. Using promptly downlinked data we find an 
uncatalogued X-ray source with an enhanced position: RA, Dec 231.54236, 
-2.14609 which is equivalent to:
   RA(J2000)  = 15h 26m 10.17s
   Dec(J2000) = -02d 08' 45.9"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This
position may be improved as more data are received; the latest position
is available at https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.11
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 190 seconds after the BAT trigger. No credible
afterglow candidate has  been found in the initial data products. The
2.7'x2.7' sub-image covers none of  the XRT error circle. The 8'x8'
region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about
18 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.138. 

Burst Advocate for this burst is T. M. Parsotan (parsotat AT umbc.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB240411B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36064
SUBJECT: GRB 240411B: LCO optical afterglow detection
DATE:    24/04/11 18:43:10 GMT
FROM:    luca.izzo@inaf.it

L. Izzo (INAF-OACn & DARK/NBI), D. B. Malesani (DAWN/NBI and Radboud Univ.), M. Della Valle and R. Martone (INAF-OACn) report:

We observed the field of GRB 240411B (Parsotan et al., GCN 36063) with the Sinistro instrument mounted on the 1-m telescope of the LCO network, located at Siding Spring Observatory, Australia. Observations started on April 11 at 17:02:54 UT (1.5 hours after the GRB trigger). We obtained a series of 3x180 s images in the r filter.

In the stacked image, we detect a new source within the XRT position, at the coordinates:

RA(J2000) = 15:26:10.17
Dec(J2000) = -02:08:46.8

We measure a preliminary magnitude of r = 21.66 +- 0.22 (AB), calibrated against nearby stars from the Pan-STARRS catalog.

This source is not visible in the Pan-STARRS catalog and is thus very likely the optical afterglow of GRB 240411B.

This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 730890.


GRB_name: GRB240411B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36065
SUBJECT: GRB 240411B: Enhanced Swift-XRT position
DATE:    24/04/11 19:09:04 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 373 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 240411B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 231.54213, -2.14640 which is equivalent
to:

RA (J2000): 15h 26m 10.11s
Dec (J2000): -02d 08' 47.0"

with an uncertainty of 2.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB240405A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36066
SUBJECT: GRB 240405A: Glowbug gamma-ray detection
DATE:    24/04/11 22:51:00 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240405A, which was also detected by Fermi/GBM (GCN 36037) and GRBAlpha (GCN 36054).  
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-05 15:06:44.536 with a duration of 56.3 s and a total significance of about 21.2 sigma.  The light curve comprises two main emission episodes from T0 to T0+1.0s and T0+48.1s to T0+56.3s.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240411B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36067
SUBJECT: GRB 240411B: OHP/T193 optical observations
DATE:    24/04/12 05:38:40 GMT
FROM:    Benjamin Schneider at MIT <bschn@mit.edu>

B. Schneider (MIT), C. Adami (LAM/Pytheas/AMU), E. Le Flocâ€™h (CEA Paris-Saclay), A. Saccardi (GEPI/Obs. de Paris) report on behalf of a larger collaboration:

We observed the field of the GRB 240411B (Parsotan et al., GCN 36063; Goad et al., GCN 36065) and its afterglow candidate (Izzo et al., GCN 36064) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. A total of 10 exposures (8x600s + 2x720s) were obtained in the r-band at 00:44:01.5 UT on 2024-04-12 (~9.2h after the trigger). In the combined frame, we detect a source consistent with the optical afterglow reported by Izzo et al. (GCN 36064).

The preliminary magnitude derived for that source is

r = 23.1 +/- 0.3 mag (AB)

The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitude is not corrected for Galactic extinction.

We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean-Pierre Troncin for the MISTRAL observations.


GRB_name: GRB240411B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36069
SUBJECT: GRB 240411B: 1.3m DFOT Optical observations
DATE:    24/04/12 10:52:24 GMT
FROM:    Amit Kumar Ror at ARIES <mitturor77894@gmail.com>

Amit K. Ror, Anshika Gupta, Rahul Gupta, Amar Aryan, Saurabh, and Shashi B.
Pandey (ARIES) report:


We observed the field of GRB 240411B detected by Swift (Parsotan et al.,
2024 GCN 36063) with the 1.3m Devasthal Fast Optical Telescope (DFOT),
located at the Devasthal Observatory of the Aryabhatta Research Institute
of Observational Sciences (ARIES), India. The observations were started on
2024-04-11 at 19:06:28 UT, i.e., ~ 3.56 hours after the BAT trigger. We
have taken multiple frames with an exposure time of 300 s in the R filter.
We stacked the images after the alignment. We clearly detected an optical
afterglow (Izzo et al., 2024, GCN 36064; Schneider et al., 2024, GCN 36067)
in our final stacked image within the error box of enhanced Swift-XRT
observation (Goad et al., 2024, GCN 36065). The estimated preliminary
magnitude is as follows:


Date Start_UT T_start-T0 (hours) Filter  Exp time (s)  Limiting magnitude

=======================================================

2024-04-11 19:06:28 UT    3.56     R     300*15     22.34 +/- 0.11


The detection of the afterglow is consistent with the observations of Izzo
et al. 2024, GCN 36064, and Schneider et al. 2024, GCN 36067.


The given magnitude value is not corrected for the Galactic and host
extinctions in the direction of the GRB afterglow. Photometric calibration
is performed using the standard stars from the USNO-B1.0 catalog. This
circular may be cited.


GRB_name: GRB240411B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36071
SUBJECT: GRB 240411B: Swift-XRT refined Analysis
DATE:    24/04/12 16:36:29 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P. D'Avanzo (INAF-OAB), J. D. Gropp (PSU), S. Dichiara (PSU), J.A.
Kennea (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U.
Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi  (INAF-IASFPA)  and
P.A. Evans report on behalf of the Swift-XRT team:

We have analysed 3.9 ks of XRT data for GRB 240411B, from 160 s to 74.6
ks after the  BAT trigger. The data comprise 10 s in Windowed Timing
(WT) mode (taken while Swift was slewing), with the remainder in Photon
Counting (PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.66 (+0.12, -0.11).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.13 (+0.38, -0.20). The
best-fitting absorption column is  consistent with the Galactic value
of 1.1 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 3.2 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.1 (+/-1.0) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.13 (+0.38, -0.20)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01221183.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB240411B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36072
SUBJECT: GRB 240411B: Swift-BAT refined analysis
DATE:    24/04/12 17:35:46 GMT
FROM:    Mike Moss at NASA GSFC <mikejmoss3@gmail.com>

A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), 
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
C. B. Markwardt (GSFC), M. J. Moss (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC),
T. Sakamoto (AGU) (i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240411B (trigger #1221183)
(Parsotan, et al., GCN Circ. 36063).  The BAT ground-calculated position is
RA, Dec = 231.562, -2.172 deg which is 
   RA(J2000)  =  15h 26m 14.8s 
   Dec(J2000) = -02d 10' 20.9" 
with an uncertainty of 3.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 53%.
 
The mask-weighted light curve shows two spikes separated by an interval of ~15 seconds. 
The estimated T90 (15-350 keV) is 33.26 +- 1.49 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.37 to T+33.92 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.69 +- 0.41.  The fluence in the 15-150 keV band is 4.9 +- 1.2 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+32.87 sec in the 15-150 keV band
is 0.9 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1221183


GRB_name: GRB240411B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36074
SUBJECT: GRB 240411B: HiPERCAM/GTC observation
DATE:    24/04/12 19:07:20 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo (CNRS, OCA, LAM), N. R. Tanvir (U. Leicester), J. F. Agui Fernandez (CAHA), A. Martin-Carrillo (UCD), C. C. Thoene (ASU-CAS), L. Izzo (INAF-OACn & DARK/NBI), J. P. U. Fynbo (DAWN/NBI), G. Lombardi (GRANTECAN), S. Geier (GRANTECAN) report:

We observed the field of GRB 240411B (Parsotan et al. GCN 36063) with HiPERCAM on the 10.4m GTC, at the Roque de Los Muchachos Observatory (Spain). We simultaneously obtained 20x60s exposure in each of the u, g, r, i, and z filters. The transparency was bad due to strong calima and the seeing was also poor. The afterglow (Izzo et al. 36064; Goad et al. GCN 36065; Schneider et al. GCN 36067; Ror et al. GCN 36069) is well detected in g, r, i and z, but not in u-band, where the limit is shallow. Observations had a mean time of 0.4256 days after the burst. We measure an r-band magnitude (AB) of r = 23.21+/- 0.08 mag as compared with field star magnitudes from the SDSS.


GRB_name: GRB240411B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36077
SUBJECT: GRB 240411B: Kinder observations with Lulin observatory 
DATE:    24/04/13 03:50:18 GMT
FROM:    Amar Aryan <amararyan941@gmail.com>

A. Aryan, T.-W. Chen, C.-S. Lin, W.-J. Hou, A. Sankar.K, Y.-C. Pan (all NCUIA), S. Yang (HNAS), M.-H. Lee, C.-H. Lai, H.-Y. Hsiao, C.-C. Ngeow, H.-C. Lin, J.-K. Guo (all NCUIA), S. Srivastav (Oxford), M. Fulton, T. Moore, C. Angus, and A. Aamer (all QUB) report: 

We observed the field of GRB 240411B (Parsotan et al., GCN 36063; Goad et al., GCN 36065; D'Avanzo et al., GCN 36071; Lien et al., GCN 36072) using the Lulin One-meter Telescope (LOT) at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen et al., AstroNote 2021-92). The optical afterglow candidate of GRB 240411B was identified (Izzo et al., GCN 36064) and followed with several instruments (Schneider et al., GCN 36067; Ror et al., GCN 36069). 

The first LOT epoch of observations started at 16:45 UT on 11 of April 2024. We followed standard IRAF (Tody D., 1993, ASPC, 52, 173) procedure to reduce the images. Further, PSF photometry was performed using DAOPHOT II (Stetson P. B., 1987, PASP, 99, 191) software. The details of the observations and the preliminary magnitudes (in the AB system) of the afterglow are as follows:

Telescope | Filter | MJD | t-t0 | Exposure | Magnitude | avg. Seeing | med. Airmass
LOT | r | 60411.698 | 1.25 hrs | 300 sec * 1 | 20.92 +/- 0.12 | 1".16 | 1.17
LOT | i | 60411.715 | 1.65 hrs | 300 sec * 1 | 20.28 +/- 0.15 | 1".0 | 1.13

The presented magnitudes are calibrated using the nearby stars from the PanSTARRS catalog  and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.14 mag in the direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB240411B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36078
SUBJECT: GRB 240411B: CrAO/ZTSh optical observations
DATE:    24/04/13 07:42:11 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <grb.alex@gmail.com>

 N. Pankov (HSE,IKI), V. Rumyantsev (CrAO), A. Pozanenko (IKI), S. Belkin
(IKI) report on behalf of IKI GRB FuN:

We observed the field of GRB 240411B (Parsotan et al., GCN 36063; Goad et
al., GCN 36065; D'Avanzo et al., GCN 36071; Lien et al., GCN 36072) with
ZTSh 2.6m telescope of CrAO observatory starting on 2024-04-11 (UT)
21:18:47. We detect optical afterglow (Izzo et al. GCN 36064; Schneider et
al. GCN 36067; Ror et al. GCN 36069; Ugarte Postigo et al. GCN 36074; Aryan
et al. GCN 36077).

Preliminary photometry of the afterglow in a combined image is following

Date UT start t-T0 Filter Exp. OT err UL(3sigma)
(mid, days) (s)
2024-04-11 21:18:47 0.283257 R 60*120 22.40 0.25 22.8

The photometry is based on several nearby USNO-B1.0 (R2) stars
USNO-B1.0


GRB_name: GRB240414A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36083
SUBJECT: GRB 240414A: Swift detection of a burst
DATE:    24/04/14 02:36:27 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


R. Caputo (GSFC), C. Gronwall (PSU), J.D. Gropp (PSU),
A. Y. Lien (U Tampa), M. J. Moss (GSFC), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 02:20:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240414A (trigger=1221714).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 184.786, +56.727 which is 
   RA(J2000) = 12h 19m 09s
   Dec(J2000) = +56d 43' 37"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of at least 60 sec, with a possible smaller
peak around T+120s (during the XRT observation).  The peak count rate
was ~2600 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 02:22:19.6 UT, 103.2 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 184.7855, 56.7381 which is equivalent to:
   RA(J2000)  = 12h 19m 8.52s
   Dec(J2000) = +56d 44' 17.2"
with an uncertainty of 4.9 arcseconds (radius, 90% containment). This
location is 39 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT data are not available at this time. 

Burst Advocate for this burst is R. Caputo (regina.caputo AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36084
SUBJECT: GRB 240414A : OHP/T193 optical counterpart detection
DATE:    24/04/14 03:35:59 GMT
FROM:    Christophe Adami at LAM <christophe.adami@lam.fr>

B. Schneider (MIT), C. Adami, O. Ilbert, S. de la Torre (LAM/Pytheas/AMU) report on behalf of a larger collaboration:

We observed the field of the GRB 240414A (Caputo et al., GCN 36083) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. In a single exposure of 60s in the r-band at 02:56:37UT on 2024-04-14 (36 min after the trigger), we clearly detect a source consistent with the XRT error:
The preliminary magnitude derived for that source is
r = 17.61 +/- 0.01 mag (AB)
The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitude is not corrected for Galactic extinction.
Spectroscopy observations using MISTRAL are currently on going.
We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean-Pierre Troncin for the MISTRAL observations.


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36085
SUBJECT: GRB 240414A : OHP/T193 redshift determination
DATE:    24/04/14 04:55:18 GMT
FROM:    Christophe Adami at LAM <christophe.adami@lam.fr>

C. Adami,  O. Ilbert, S. de la Torre (LAM/Pytheas/AMU), A. de Ugarte Postigo (OCA/LAM), report on behalf 
of a larger collaboration:

We observed the optical counterpart of GRB 240414A (Caputo et al., GCN 36083, Schneider et al., GCN 36084)
in spectroscopy with the MISTRAL instrument in blue mode using the T193cm telescope at Observatoire de
Haute-Provence (France).

We detect the optical GRB afterglow at RA = 12:19:08.08 and DEC = +56:44:28.8 (J2000).

Our spectra cover the wavelength range 4200-8000 AA and consist of 3 exposures of 900 seconds each.
Observations started at 03:17:09 UT on April 14, 2024 (~57 min after the X-ray trigger). We detect a strong
continuum with absorption features which we identify as AlII, AlIII, FeII, MnII and MgII at a common redshift
of z=1.833 that we interpret as the redshift of GRB 240414A.

Our photometric data reduction continue with g' band observations.

We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean-Pierre Troncin
for the MISTRAL observations.


GRB_name: GRB240414A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36087
SUBJECT: GRB 240414A: Redshift confirmation from GTC/OSIRIS+
DATE:    24/04/14 07:07:37 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo (CNRS, OCA, LAM), G. Lombardi (GRANTECAN), J. F. Agui Fernandez (CAHA), C. C. Thoene (ASU-CAS), J. P. U. Fynbo (DAWN/NBI), L. Izzo (INAF-OACn & DARK/NBI), N. R. Tanvir (U. Leicester), A. Martin-Carrillo (UCD), S. Geier (GRANTECAN) report:

We have obtained spectroscopy of the afterglow of GRB 240414A (Caputo et al. GCN 36083, Schneider et al. GCN 36084) with OSIRIS+ on the 10.4m GTC on the Roque de los Muchachos Observatory (Spain). The observation consisted of 3x900s exposure with grism R1000B covering the range between 3600 and 7880 AA at a mean epoch 2.11 hrs after the burst.

We detect a strong continuum over all the spectral range with absorption features that we identify as due to OI, CII, SiIV, SiII, CIV, AlII, NiII, AlIII, ZnII, FeII and MnII, as well as SiII* and FeII*, all at a common redshift of 1.833, consistent with the redshift determined by Adami et al. (GCN 36085).

Additionally, we identify an absorption system with CIV and MgII at z=1.703 and another one with MgII at z=1.067. Finally, there is a further strong and slightly broadened feature at 4056 AA that could be due to an intervening system of CIV at z=1.618, but there are no other related features to confirm it.


GRB_name: GRB240411A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36090
SUBJECT: IPN triangulation of GRB 240411A
DATE:    24/04/14 14:00:48 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks,  A. Lysenko, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

The long-duration GRB 240411A
(Fermi-GBM detection: The Fermi GBM team, GCN 36061;
GRBAlpha detection: Pal et al., GCN 36068)
was detected by Fermi (GBM trigger 734492703),
INTEGRAL (SPI-ACS), Swift (BAT), Konus-Wind, and GRBAlpha
at about 6298 s UT (01:44:58).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  246.889 (16h 27m 33s) +45.010 (+45d 00' 36")
 Corners:
  251.205 (16h 44m 49s) +41.318 (+41d 19' 05")
  251.479 (16h 45m 55s) +41.818 (+41d 49' 03")
  241.660 (16h 06m 38s) +48.434 (+48d 26' 03")
  241.553 (16h 06m 13s) +47.881 (+47d 52' 53")
 ---------------------------------------------
The error box area is 4.6 sq. deg, and its maximum
dimension is 9.8 deg (the minimum one is 29 arcmin).
The Sun distance was 111 deg.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240411_T06302/IPN/


The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.


GRB_name: GRB240410A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36093
SUBJECT: IPN triangulation of GRB 240410A
DATE:    24/04/14 16:23:21 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The long-duration GRB 240410A
was detected by INTEGRAL (SPI-ACS), Swift (BAT), Konus-Wind,
and Mars-Odyssey (HEND) at about 73409 s UT (20:23:29).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  109.832 (07h 19m 20s) +30.179 (+30d 10' 43")
 Corners:
  110.414 (07h 21m 39s) +32.327 (+32d 19' 37")
  110.411 (07h 21m 39s) +32.546 (+32d 32' 46")
  109.265 (07h 17m 04s) +27.655 (+27d 39' 19")
  109.268 (07h 17m 04s) +27.350 (+27d 21' 01")
 ---------------------------------------------
The error box area is 957 sq. arcmin, and its maximum
dimension is 5.3 deg (the minimum one is 3 arcmin).
The Sun distance was 86 deg.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240410_T73409/IPN/

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.


GRB_name: GRB240414A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36095
SUBJECT: Swift GRB 240414A: Global MASTER-Net observations report
DATE:    24/04/14 17:28:49 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 240414A ( R. Caputo et al., GCN 36083) errorbox  53869 sec after notice time and 53925 sec after trigger time at 2024-04-14 17:19:21 UT, with upper limit up to  17.3 mag. Observations started at twilight.  The observations began at zenith distance = 32 deg. The sun  altitude  is -10.0 deg. 

The galactic latitude b = 60 deg., longitude l = 131 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2422039

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   54015 |      MASTER-Tavrida |   C |   180 | 17.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36097
SUBJECT: GRB 240414A: Skynet Optical Afterglow Observations
DATE:    24/04/14 18:19:53 GMT
FROM:    Dylan Dutton at UNC Chapel Hill <ddutton59@gmail.com>

Dylan Dutton, Megan Dubay, Ruide Fu, Donovan Schlekat, Daniel Reichart, Joshua Haislip, Vladimir Kouprianov, Daniel Caton, Lee Hawkins, Dean Glace, Daryl Janzen, Kim Janzen, James Davidson, Edward Murphy, and Carlos Salgado report on behalf of the Skynet Robotic Telescope Network at the University of North Carolina at Chapel Hill.

We observed the field of GRB 240414A with three of our North American robotic telescopes. The first detection occurred at 02:36:17 UTC on Apr 14 2024, approximately 15 minutes after the trigger reported by Swift (Caputo et al., GCN 36083).

We obtained multiple exposures in the B, V, and R filters. Exposure lengths were calculated using our automated exposure length scaling model.

We detect the optical afterglow with coordinates consistent to those reported by OHP/T193 (B. Schneider et al., GCN 36084).

The coordinates are:
R.A. (J2000): 12:19:08.12
Dec. (J2000): 56:44:28.70

We report the photometry below. We estimate a temporal index of about -0.9 and spectral index of about -0.5.

ExpLen | Filter | Mag   | Mag Error  | MJD         
------------------------------------------------
51.99  | B      | 17.02 | 0.066      | 60414.108
52.82  | V      | 16.92 | 0.068      | 60414.110
27.18  | R      | 16.46 | 0.086      | 60414.111
76.20  | V      | 17.77 | 0.122      | 60414.115
38.54  | R      | 17.02 | 0.117      | 60414.117
103.4  | B      | 17.86 | 0.096      | 60414.120
52.39  | R      | 17.26 | 0.117      | 60414.124
138.1  | V      | 17.45 | 0.084      | 60414.128
63.67  | R      | 17.13 | 0.117      | 60414.130
300    | R      | 18.77 | 0.116      | 60414.204
300    | R      | 18.61 | 0.101      | 60414.207
300    | V      | 19.04 | 0.064      | 60414.208
300    | V      | 19.03 | 0.063      | 60414.208
300    | R      | 18.89 | 0.126      | 60414.211
300    | V      | 18.85 | 0.054      | 60414.211
300    | V      | 18.85 | 0.054      | 60414.211
300    | R      | 18.54 | 0.091      | 60414.214
300    | V      | 18.97 | 0.059      | 60414.215
300    | V      | 18.98 | 0.059      | 60414.215
300    | R      | 18.92 | 0.134      | 60414.218
300    | V      | 19.03 | 0.063      | 60414.218
300    | V      | 19.03 | 0.063      | 60414.218
300    | R      | 18.94 | 0.138      | 60414.221
300    | V      | 19.03 | 0.062      | 60414.222
300    | V      | 19.04 | 0.062      | 60414.222
300    | R      | 18.67 | 0.106      | 60414.225
300    | V      | 19.12 | 0.065      | 60414.225
300    | V      | 19.05 | 0.061      | 60414.225
300    | R      | 18.67 | 0.106      | 60414.228
300    | V      | 19.15 | 0.070      | 60414.229
300    | V      | 19.16 | 0.070      | 60414.229
300    | R      | 18.96 | 0.137      | 60414.232
300    | V      | 19.16 | 0.069      | 60414.233
300    | V      | 19.20 | 0.072      | 60414.233
300    | R      | 18.72 | 0.113      | 60414.236
300    | V      | 19.30 | 0.076      | 60414.236
300    | V      | 19.29 | 0.075      | 60414.236
300    | V      | 19.16 | 0.071      | 60414.240
300    | V      | 19.21 | 0.075      | 60414.240
300x3  | R      | 19.02 | 0.138      | 60414.243
300x3  | R      | 19.26 | 0.090      | 60414.295
300x3  | R      | 19.22 | 0.088      | 60414.306
300x3  | R      | 19.35 | 0.080      | 60414.316
300x3  | R      | 19.54 | 0.092      | 60414.327
300x3  | R      | 19.35 | 0.159      | 60414.337
300x5  | R      | 19.59 | 0.147      | 60414.351

Our images have been calibrated using stars from the APASS catalog.


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36100
SUBJECT: GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
DATE:    24/04/14 21:27:52 GMT
FROM:    I. Peretto at MarSEC (Marana Space Explorer Center) <ricerca@marsec.org>

Ivo Peretto (MarSEC, Marana Space Explorer Center, Marana Di Crespadoro, VI, Italy)

Member of:
UAI/SSV - Unione Astrofili Italiani/Sezione Stelle Variabili, GRB section.
AAVSO (American Association Variable Stars Observers)

In collaboration with: Stefano Lora and Giovanni Furlato (MarSEC, Marana Space Explorer Center, Marana di Crespadoro, VI, Italy) 

report:
We imaged the field of GRB 240414A detected by SWIFT(trigger=1221714)
with the telescope  14â€ RC Officine Stellari of MarSEC (Marana Space Explorer Center).

The observations with a series of 120 sec exposures started at 2024-01-01 18:18 UT, 958 min. after the GRB trigger, with a Ritchey-Chretien telescope D=360 mm f/ 8.

at the following position:

RA(J2000) = 12h 19m 09s
Dec(J2000) = +56d 43' 37"


Weather conditions were medium with Moon illuminated 40,5%.

We co-added 30 exposures of 120 sec each.

Start T0+      End T0+       R lim.
 958 min       1018 min       20.82

We did not found any optical counterpart in A.R. 12 19 09, DEC. +56 43 37 position and in the error box of the XRT candidate.
ref.: GCN Circular 36083

Magnitudes were estimated with the APASS and
are not corrected for galactic dust extinction.

Reference:
https://www.marsec.org/

The message may be cited. 


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36101
SUBJECT: GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
DATE:    24/04/14 21:59:49 GMT
FROM:    Damien Turpin at CEA-Saclay <dturpin-astro@hotmail.com>

D. Turpin (CEA Paris-Saclay), B. Schneider (MIT), C. Adami, Ny Avo Rakotondrainibe, Olivier Ilbert, S. Basa (LAM/Pytheas/AMU), A. de Ugarte Postigo (OCA/LAM), E. Le Floc'h (CEA Paris-Saclay), S. D. Vergani (GEPI, Obs. de Paris), report on behalf of a larger collaboration:

We performed a second epoch of observation of the GRB 240414A afterglow candidate (Caputo et al., GCN 36083, Schneider et al. GCN 36084, Dutton et al. GCN 36097) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. After stacking 8 r-band images (total exp = 4080sec), we clearly detect the optical afterglow with the following preliminary magnitude:
-----------------------------------------------
T-T0 (in days, midtime) | mag | filter
-----------------------------------------------
0.7397 | 21.84 Â± 0.16 mag (AB) | r'
-----------------------------------------------

We also report the g-band magnitude of the afterglow for the previous night (2x120s):
-----------------------------------------------
T-T0 (in days, midtime) | mag | filter
-----------------------------------------------
0.0645 | 18.39 Â± 0.03 mag (AB) | g'
-----------------------------------------------
Based on our two epochs in r-band, we obtain a temporal slope alpha ~ -1.1 which is roughly consistent with the one of Dutton et al. GCN 36097.

We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean-Pierre Troncin for the MISTRAL observations.


GRB_name: GRB240414A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36102
SUBJECT: GRB 240414A: Enhanced Swift-XRT position
DATE:    24/04/14 22:35:36 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 872 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 240414A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 184.78364, +56.74056 which is equivalent
to:

RA (J2000): 12h 19m 8.07s
Dec (J2000): +56d 44' 26.0"

with an uncertainty of 3.2 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36103
SUBJECT: GRB240414A : J-band upper limits from WINTER
DATE:    24/04/14 22:55:41 GMT
FROM:    Viraj Karambelkar at Indian Inst of Tech,Bombay <karambelkarvraj21197@gmail.com>

Viraj Karambelkar (Caltech), Tomas Ahumada (Caltech), Geoffrey Mo (MIT),
Danielle Frostig (MIT), Robert Stein (Caltech), Nathan Lourie (MIT), Robert
Simcoe (MIT), Mansi Kasliwal (Caltech)



We observed the field of the GRB 240414A (GCN #36084, #36083, #36087, #36088,
#36093, #36095, #36097, #36100, #36101) in the near-infrared J-band with
the Palomar 1-m telescope, equipped with the 1 square degree WINTER camera
(Lourie et al. 2020).

Our observations started at UTC 2024-04-14T20:16:20 (MJD 60414.45) and
lasted a total of 50 minutes. The images were processed through the WINTER
data reduction pipeline implemented using mirar (
https://zenodo.org/records/10888437), with image subtraction performed
relative to reference images built from the UKIRT Hemisphere Survey (Dye et
al. 2017).

We do not detect the optical counterpart reported by GCN #36084, #36085,
#36097, #36101 in the J-band WINTER images, and derive a limiting mag. of J
~ 19 mag (AB).

WINTER (Wide-field INfrared Transient ExploreR) is a partnership between
MIT and Caltech, housed at Palomar Observatory, and funded by NSF MRI, NSF
AAG, the David and Lucille Packard Foundation, and the MIT Kavli Institute
for Astrophysics and Space Research


GRB_name: GRB240414A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36104
SUBJECT: GRB 240414A: Swift-XRT refined Analysis
DATE:    24/04/15 03:00:26 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), M.G. Bernardini
(INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA) and
P.A. Evans report on behalf of the Swift-XRT team:

We have analysed 5.4 ks of XRT data for GRB 240414A, from 9.9 ks to
74.3 ks after the  BAT trigger. The data are entirely in Photon
Counting (PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.0 (+/-0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.0 (+0.4, -0.3). The
best-fitting absorption column is  3.7 (+8.5, -2.3) x 10^20 cm^-2,
consistent with the Galactic value of 1.4 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 3.2 x 10^-11 (3.5 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.7 (+8.5, -2.3) x 10^20 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.0 (+0.4, -0.3)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01221714.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB240415A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36107
SUBJECT: GRB 240415A: Fermi GBM Final Real-time Localization
DATE:    24/04/15 06:38:26 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 06:26:57 UT on 15 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240415A (trigger 734855222.604114 / 240415269).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 201.6, Dec = 75.7 (J2000 degrees, equivalent to J2000 13h 26m, 75d 42'), with a statistical uncertainty of 8.2 degrees.

The angle from the Fermi LAT boresight is 110.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240415269/quicklook/glg_skymap_all_bn240415269.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240415269/quicklook/glg_healpix_all_bn240415269.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240415269/quicklook/glg_lc_medres34_bn240415269.gif


GRB_name: GRB240415A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36108
SUBJECT: GRB 240415A: Swift detection of a burst
DATE:    24/04/15 07:14:36 GMT
FROM:    David Palmer at LANL <palmer@lanl.gov>


M. J. Moss (GSFC), K. L. Page (U Leicester) and D. M. Palmer (LANL)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 06:26:53 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240415A (trigger=1221874).  Due to a telemetry gap, only
limited information is available, specifically the detector plane
histogram and associated metadata.  Ground analysis of this histogram
finds a source at 
RA, Dec 129.128, +73.169 which is 
   RA(J2000) = 08h 36m 31s
   Dec(J2000) = +73d 10' 08"
The metadata indicates a trigger duration of 1 s, which does not distinguish
between a short or a long burst. 

We note that this trigger time and position is consistent with Fermi GBM's
detection of GRB 240415A (GCN 36107). 

Burst Advocate for this burst is M. J. Moss (mikejmoss3 AT gmail.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB240415A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36109
SUBJECT: GRB 240415A: Prompt Swift-XRT observations
DATE:    24/04/15 08:00:44 GMT
FROM:    P.A. Evans at U. Leicester <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), K.L. Page (U. Leicester) and M. J. Moss (GSFC)
report on behalf of the Swift-XRT team:

The automated Swift slew to GRB 240415A (BAT trigger 1221874; Moss et al.,
GCN Circ. 36108) was delayed due to an Earth limb constraint. 

The XRT began observing the field at 07:21:58.2 UT, 3305 seconds
after the BAT trigger. Using promptly downlinked data we find an
uncatalogued X-ray source located at RA, Dec 129.19096 73.14608 which
is equivalent to:
   RA(J2000)  = 08h 36m 45.83s
   Dec(J2000) = +73d 08' 45.9"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This is
105 arcseconds from the BAT position, inside the BAT error circle. This
position may be improved as more data are received; the latest position
is available at https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.49 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 6.5
(+3.49/-2.94) x 10^21 cm^-2 (90% confidence). 


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36111
SUBJECT: GRB 240414A: AKO Optical Upper Limit
DATE:    24/04/15 10:28:18 GMT
FROM:    Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>

Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International
Astronomical Center in Abu Dhabi, UAE), Nidhal Guessoum and Dalya Akl
(American University of Sharjah, UAE), report:

As a follow-up for the GRB 240414A (Caputo et al., GCN 36083), where the
optical afterglow was detected by (Schneider et al., GCN 36084; Adami et
al., GCN 36085; de Ugarte Postigo et. al., GCN 36087; Dutton et al., GCN
36097; Turpin et. al., GCN 36101).

We observed the field of this GRB using our 0.36m f/7.7 robotic telescope.
Our observation started on 14 April 2024 at 21:00:26 UT, 18.7 hours after
the GRB trigger. No new optical source was detected within the error box
(Osborne et al., GCN 36102) down to 19.9 magnitude in the stacked image
(total 20x180s, Ic band). The magnitude was estimated using the Atlas
catalogue as a reference, and it is not corrected for galactic extinction.

Our non-detection is consistent with the results of (Niwano et al., GCN
36088; Peretto et al., GCN 36100; Karambelkar et al., GCN 36103).


GRB_name: GRB240414B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36112
SUBJECT: GRB 240414B: Fermi GBM Final Real-time Localization
DATE:    24/04/15 12:32:00 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 02:20:39 UT on 14 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240414B (trigger 734754044.261764 / 240414098).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 188.2, Dec = 58.1 (J2000 degrees, equivalent to J2000 12h 32m, 58d 06'), with a statistical uncertainty of 4.7 degrees.

The angle from the Fermi LAT boresight is 47.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240414098/quicklook/glg_skymap_all_bn240414098.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240414098/quicklook/glg_healpix_all_bn240414098.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240414098/quicklook/glg_lc_medres34_bn240414098.gif


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36113
SUBJECT: GRB 240414A: Mondy optical observations
DATE:    24/04/15 13:04:11 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB-IKI-FuN:

We observed the field of GRB 240414A (Caputo et. al., GCN 36083) at redshift z=1.833 (Adami et al., GCN 36085; de Ugarte Postigo et al., GCN 36087) with 1.5-meter AZT-33IK telescope of Sayan observatory at Mondy. The observations were started on 2024-04-14 (UT) 13:56:41, i.e. ~12 hr since the Swift trigger. We took 45 frame 120 s each in the R-filter.
The optical counterpart (Schneider et al., GCN 36084; Adami et al., GCN 36085; de Ugarte Postigo et al., GCN 36087; Niwano et al., GCN 36088; Lipunov et al., GCN 36095; Dutton et al., GCN 36097; Peretto, GCN 36100; Turpin et al., GCN 36101; Karambelkar et al., GCN 36103) is well detected in the stacked image at coordinates of (J2000) 12:19:08.09 +56:44:28.8. Preliminary photometry of the optical source is following:

Date       UT_start  t-T0     Filter Exp.  OT    err  UL(3sigma)
                    (mid, days)     (s)
2024-04-14 13:56:41  0.51395  R     44*120 20.60 0.12 22.2

The magnitudes were calibrated with respect to nearby USNO-B1.0 stars.
Assuming no spectral evolution between earlier observations(Turpin et al., GCN 36101),  we  estimate a power law decay index to be alpha~1.2, which is in agreement with SkyNet observations (Dutton et al., GCN 36097).


GRB_name: GRB240402B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36114
SUBJECT: LXT 240402A/GRB 240402B: Swift follow-up observations
DATE:    24/04/15 13:21:33 GMT
FROM:    Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo@ucd.ie>

A. Martin-Carrillo (UCD), S. Campana (INAF/Brera), D. B. Malesani (DAWN/NBI & Radboud Univ.), A. J. Levan (Radboud Univ.), G. Pugliese (Amsterdam), D. Xu (NAOC/CAS), N. R. Tanvir (Leicester), P. G. Jonker (Radboud Univ.), A. Rossi (INAF-OAS), P. Oâ€™Brien (Leicester) report on behalf of the Stargate collaboration:

Following up the LEIA trigger LXT 240402A (Xu et al., GCN 36016) associated with the Konus-Wind GRB 240402B (Ridnaia et al., GCN 3628) and the detection of its X-ray counterpart (Jia et al., GCN 36022) a series of Swift follow-up observations (PI Xu, ID: 203030 and PI Martin-Carrillo, ID: 20382) were performed between April 7 and April 14, with a total exposure time of 8 ks.

Combining all the data, a source is well detected with a count rate of 1.9 (+0.7, -0.6) x 10^-3 count s^-1 at the coordinates (J2000):

RA: 16:21:47.75 (245.4490);
Dec: +25:45:45.9â€™ (25.7627);
Error: 5.8â€ (90% confidence).

Using the spectral parameters of the EP-FXT detection (Jia et al., GCN 36022), this corresponds to an observed flux of 7.7*10^-14 erg cm^-2 s^-1. Assuming a mid-point for the Swift observations of 8.5 days after the LEIA trigger, and using a single power-law decay, the X-ray flux decays with an approximate index -1.2, typical for a GRB afterglow.

The source centroid lies within 1.5" from the optical counterpart reported by Levan et al. (GCN 36025) and Yang et al. (GCN 36027). The reduced localisation error strengthens its association with the proposed optical counterpart.

We thank the Neil Gehrels Swift Observatory team for making these ToO observations possible.


GRB_name: GRB240414A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36115
SUBJECT: GRB 240414A: Swift/UVOT Detection
DATE:    24/04/15 13:29:21 GMT
FROM:    Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>

M. H. Siegel (PSU) and R. Caputo (GSFC) report on behalf of the
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240414A
9754s after the BAT trigger (Caputo et al., GCN Circ. 36083). A source consistent
with the XRT position (Obsorne et al., GCN Circ. 36102) and the previously reported
optical counterpart (Schneider et al., GCN Circ. 36084, Aryan et al., GCN Circ. 36094,
Dutton et al., GCN Circ. 36097, Xu et al., GCN Circ. 36105, Pankov et al., GCN Circ. 36113)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  12:19:08.09 = 184.78370 (deg.)
    Dec (J2000) = +56:44:28.6  =  56.74127 (deg.)
with an estimated uncertainty of 0.4 arc sec. (radius, 90% confidence).

Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
b                 9754        10628          853      19.23+/-0.07
uvm2             15403        16303          885            >20.33
u                22136        22862          707      19.29+/-0.11
v                62457        62769          302            >19.60
uvw1             16310        22129         1262      20.04+/-0.18
uvw2             26698        27465          755            >20.54

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36117
SUBJECT: GRB 240414A: Photometric observation from 2.2m CAHA
DATE:    24/04/15 15:11:19 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo (CNRS, OCA, LAM), J.F. Agui Fernandez (CAHA), C.C. Thoene (ASU-CAS), Y. Calatayud-Borras and S. Gongora (both CAHA) report:

We observed the field of GRB 240414A (Caputo et al. GCN 36083) to obtain photometry of the optical afterglow (Schneider et al. GCN 36084, Dutton et al. GCN 36097, Turpin et al. GCN 36101, Pankov et al. GCN 36113, Siegel et al. GCN 36115) at a redshift of 1.833 (Adami et al. GCN 36085, de Ugarte Postigo et al. GCN 36087). The observation was performed with CAFOS, mounted on the 2.2m Calar Alto Telescope, in Almeria (Spain). Our imaging started at 2024-04-14T23:28:42 UT (21.14 hr after the burst onset) and consisted of 5x200s exposures in each of the g, r, and i bands

The afterglow is well detected in all three bands, and had decayed to r(AB) = 22.11+/-0.18 mag, as compared to field stars of the SDSS. Further observations are scheduled.


GRB_name: GRB240415A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36118
SUBJECT: GRB 240415A: Mondy optical transient detection
DATE:    24/04/15 16:15:54 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB-IKI-FuN:

We observed the field of GRB 240415A (Fermi GBM team, GCN 36107; Moss et al., GCN 36108, Evans et al., GCN 36109) with 1.5-meter AZT-33IK telescope of Sayan observatory at Mondy. The observations were started on 2024-04-15 (UT) 14:33:22, i.e. ~8 hr since the Fermi GBM trigger. We took 30 frames 120 s each in the R-filter. We detect a possible optical counterpart in the stacked image at coordinates of (J2000)  08:36:45.26    73:08:47.6 with uncertainties of 0.4 arcsec in both coordinates. 
Preliminary photometry of the optical source is following:

Date       UT_start  MJD           Filter Exp.  OT    err  UL(3sigma)
                    (mid, days)           (s)
2024-04-15 14:33:22  60415.627345  R     44*120 18.84 0.08 21.9

The magnitudes were calibrated using nearby USNO-B1.0 stars.


GRB_name: GRB240415A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36119
SUBJECT: Fermi GRB 240415A: Global MASTER-Net observations report
DATE:    24/04/15 19:15:28 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240415A ( Fermi GBM team, GCN 36107) errorbox  43102 sec after notice time and 43137 sec after trigger time at 2024-04-15 18:25:55 UT, with upper limit up to  18.7 mag. The observations began at zenith distance = 35 deg. The sun  altitude  is -20.0 deg. 

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 240415A errorbox  43114 sec after notice time and 43149 sec after trigger time at 2024-04-15 18:26:07 UT, with upper limit up to  18.6 mag. The observations began at zenith distance = 38 deg. The sun  altitude  is -25.1 deg. 

The galactic latitude b = 42 deg., longitude l = 120 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2423215

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   43168 | 2024-04-15 18:25:55 |      MASTER-Tavrida | (12h 41m 57.43s , +75d 02m 45.2s) |   C |    60 | 18.3 |        
   43180 | 2024-04-15 18:26:07 |   MASTER-Kislovodsk | (13h 58m 04.46s , +75d 29m 04.7s) |   C |    60 | 17.6 |        
   43180 | 2024-04-15 18:26:07 |   MASTER-Kislovodsk | (14h 14m 02.58s , +75d 02m 20.5s) |   C |    60 | 18.5 |        
   43260 | 2024-04-15 18:27:27 |   MASTER-Kislovodsk | (13h 22m 54.58s , +79d 18m 44.3s) |   C |    60 | 17.8 |        
   43260 | 2024-04-15 18:27:27 |   MASTER-Kislovodsk | (13h 44m 16.06s , +78d 51m 50.7s) |   C |    60 | 18.5 |        
   43340 | 2024-04-15 18:28:47 |   MASTER-Kislovodsk | (13h 17m 15.80s , +73d 35m 59.5s) |   C |    60 | 17.8 |        
   43340 | 2024-04-15 18:28:47 |   MASTER-Kislovodsk | (13h 31m 44.89s , +73d 10m 02.8s) |   C |    60 | 18.5 |        
   43374 | 2024-04-15 18:29:21 |      MASTER-Tavrida | (13h 24m 13.00s , +76d 57m 02.6s) |   C |    60 | 18.4 |        
   43420 | 2024-04-15 18:30:07 |   MASTER-Kislovodsk | (12h 51m 52.86s , +76d 57m 52.8s) |   C |    60 | 18.3 |        
   43420 | 2024-04-15 18:30:07 |   MASTER-Kislovodsk | (12h 33m 18.95s , +77d 23m 31.1s) |   C |    60 | 17.5 |        
   43446 | 2024-04-15 18:30:33 |      MASTER-Tavrida | (13h 56m 37.00s , +73d 10m 16.5s) |   C |    60 | 18.3 |        
   43518 | 2024-04-15 18:31:45 |      MASTER-Tavrida | (13h 21m 10.17s , +71d 15m 43.7s) |   C |    60 | 18.4 |        
   43593 | 2024-04-15 18:33:00 |      MASTER-Tavrida | (11h 42m 00.08s , +75d 01m 17.2s) |   C |    60 | 18.5 |        
   43666 | 2024-04-15 18:34:13 |      MASTER-Tavrida | (12h 33m 06.72s , +71d 13m 56.3s) |   C |    60 | 18.6 |        
   43701 | 2024-04-15 18:34:48 |   MASTER-Kislovodsk | (14h 44m 19.50s , +79d 16m 36.9s) |   C |    60 | 17.6 |        
   43701 | 2024-04-15 18:34:48 |   MASTER-Kislovodsk | (15h 05m 01.93s , +78d 48m 27.9s) |   C |    60 | 18.4 |        
   43781 | 2024-04-15 18:36:08 |   MASTER-Kislovodsk | (12h 55m 54.06s , +81d 11m 28.9s) |   C |    60 | 17.8 |        
   43781 | 2024-04-15 18:36:08 |   MASTER-Kislovodsk | (13h 21m 39.24s , +80d 44m 24.4s) |   C |    60 | 18.4 |        
   43861 | 2024-04-15 18:37:28 |   MASTER-Kislovodsk | (14h 51m 26.51s , +77d 23m 02.0s) |   C |    60 | 17.5 |        
   43861 | 2024-04-15 18:37:28 |   MASTER-Kislovodsk | (15h 09m 51.40s , +76d 55m 31.1s) |   C |    60 | 18.2 |        
   43942 | 2024-04-15 18:38:49 |   MASTER-Kislovodsk | (12h 23m 31.82s , +73d 36m 49.8s) |   C |    60 | 17.9 |        
   43942 | 2024-04-15 18:38:49 |   MASTER-Kislovodsk | (12h 38m 13.66s , +73d 11m 56.7s) |   C |    60 | 18.6 |        
   43947 | 2024-04-15 18:38:54 |      MASTER-Tavrida | (11h 40m 21.90s , +79d 27m 06.2s) |   C |    60 | 18.5 |        
   44242 | 2024-04-15 18:43:49 |      MASTER-Tavrida | (12h 41m 57.04s , +75d 02m 13.5s) |   C |    60 | 18.6 |        
   44269 | 2024-04-15 18:44:16 |   MASTER-Kislovodsk | (14h 14m 03.95s , +75d 02m 14.5s) |   C |    60 | 18.2 |        
   44269 | 2024-04-15 18:44:16 |   MASTER-Kislovodsk | (13h 57m 52.27s , +75d 28m 52.9s) |   C |    60 | 17.5 |        
   44314 | 2024-04-15 18:45:01 |      MASTER-Tavrida | (13h 13m 41.15s , +75d 02m 50.4s) |   C |    60 | 18.6 |        
   44350 | 2024-04-15 18:45:37 |   MASTER-Kislovodsk | (13h 44m 12.27s , +78d 52m 16.9s) |   C |    60 | 18.1 |        
   44350 | 2024-04-15 18:45:37 |   MASTER-Kislovodsk | (13h 22m 33.47s , +79d 19m 00.8s) |   C |    60 | 17.5 |        
   44384 | 2024-04-15 18:46:11 |      MASTER-Tavrida | (13h 24m 18.65s , +76d 58m 13.6s) |   C |    60 | 18.5 |        
   44429 | 2024-04-15 18:46:57 |   MASTER-Kislovodsk | (13h 16m 59.43s , +73d 35m 27.9s) |   C |    60 | 17.5 |        
   44429 | 2024-04-15 18:46:57 |   MASTER-Kislovodsk | (13h 31m 36.58s , +73d 09m 38.3s) |   C |    60 | 18.3 |        
   44455 | 2024-04-15 18:47:22 |      MASTER-Tavrida | (14h 00m 34.32s , +76d 57m 07.8s) |   C |    60 | 18.3 |        
   44510 | 2024-04-15 18:48:17 |   MASTER-Kislovodsk | (12h 33m 08.21s , +77d 25m 41.9s) |   C |    60 | 17.4 |        
   44510 | 2024-04-15 18:48:17 |   MASTER-Kislovodsk | (12h 51m 56.28s , +77d 00m 14.0s) |   C |    60 | 18.2 |        
   44525 | 2024-04-15 18:48:33 |      MASTER-Tavrida | (13h 56m 47.31s , +73d 10m 32.5s) |   C |    60 | 18.4 |        
   44590 | 2024-04-15 18:49:37 |   MASTER-Kislovodsk | (14h 21m 25.41s , +71d 41m 13.5s) |   C |    60 | 17.3 |        
   44590 | 2024-04-15 18:49:37 |   MASTER-Kislovodsk | (14h 34m 39.37s , +71d 15m 19.0s) |   C |    60 | 18.1 |        
   44597 | 2024-04-15 18:49:44 |      MASTER-Tavrida | (14h 24m 47.23s , +73d 10m 17.6s) |   C |    60 | 18.3 |        
   44670 | 2024-04-15 18:50:57 |   MASTER-Kislovodsk | (14h 43m 16.62s , +79d 17m 39.9s) |   C |    60 | 17.5 |        
   44670 | 2024-04-15 18:50:57 |   MASTER-Kislovodsk | (15h 04m 56.57s , +78d 49m 56.8s) |   C |    60 | 18.3 |        
   44877 | 2024-04-15 18:54:24 |      MASTER-Tavrida | (13h 21m 14.79s , +71d 15m 40.9s) |   C |    60 | 18.5 |        
   44950 | 2024-04-15 18:55:37 |   MASTER-Kislovodsk | (12h 55m 52.40s , +81d 11m 20.1s) |   C |    60 | 17.3 |        
   44950 | 2024-04-15 18:55:37 |   MASTER-Kislovodsk | (13h 21m 27.72s , +80d 44m 44.2s) |   C |    60 | 17.9 |        
   45031 | 2024-04-15 18:56:58 |   MASTER-Kislovodsk | (14h 51m 29.36s , +77d 21m 43.6s) |   C |    60 | 17.0 |        
   45031 | 2024-04-15 18:56:58 |   MASTER-Kislovodsk | (15h 09m 43.58s , +76d 54m 21.0s) |   C |    60 | 17.6 |        
   45111 | 2024-04-15 18:58:18 |   MASTER-Kislovodsk | (12h 23m 29.80s , +73d 37m 50.3s) |   C |    60 | 17.4 |        
   45111 | 2024-04-15 18:58:18 |   MASTER-Kislovodsk | (12h 38m 11.43s , +73d 13m 26.0s) |   C |    60 | 18.0 |        
   45165 | 2024-04-15 18:59:12 |      MASTER-Tavrida | (13h 46m 25.65s , +71d 16m 16.2s) |   C |    60 | 18.4 |        
   45191 | 2024-04-15 18:59:38 |   MASTER-Kislovodsk | (13h 57m 39.21s , +75d 28m 58.0s) |   C |    60 | 17.2 |        
   45191 | 2024-04-15 18:59:38 |   MASTER-Kislovodsk | (14h 13m 58.40s , +75d 03m 07.1s) |   C |    60 | 17.8 |        
   45240 | 2024-04-15 19:00:27 |      MASTER-Tavrida | (11h 42m 12.12s , +75d 01m 49.4s) |   C |    60 | 18.5 |        
   45271 | 2024-04-15 19:00:58 |   MASTER-Kislovodsk | (13h 22m 29.72s , +79d 18m 43.9s) |   C |    60 | 17.2 |        
   45271 | 2024-04-15 19:00:58 |   MASTER-Kislovodsk | (13h 44m 13.71s , +78d 52m 49.5s) |   C |    60 | 17.9 |        
   45317 | 2024-04-15 19:01:44 |      MASTER-Tavrida | (12h 13m 40.94s , +75d 01m 28.4s) |   C |    60 | 18.7 |        
   45351 | 2024-04-15 19:02:18 |   MASTER-Kislovodsk | (13h 16m 54.83s , +73d 36m 29.9s) |   C |    60 | 17.3 |        
   45351 | 2024-04-15 19:02:18 |   MASTER-Kislovodsk | (13h 31m 32.67s , +73d 11m 28.0s) |   C |    60 | 17.8 |        
   45388 | 2024-04-15 19:02:55 |      MASTER-Tavrida | (12h 33m 18.22s , +71d 13m 42.0s) |   C |    60 | 18.6 |        
   45432 | 2024-04-15 19:03:39 |   MASTER-Kislovodsk | (12h 32m 59.58s , +77d 25m 49.4s) |   C |    60 | 17.2 |        
   45432 | 2024-04-15 19:03:39 |   MASTER-Kislovodsk | (12h 51m 46.06s , +77d 01m 20.2s) |   C |    60 | 17.9 |        
   45460 | 2024-04-15 19:04:07 |      MASTER-Tavrida | (12h 58m 31.22s , +71d 15m 36.2s) |   C |    60 | 18.7 |        
   45512 | 2024-04-15 19:04:59 |   MASTER-Kislovodsk | (14h 21m 31.48s , +71d 41m 32.0s) |   C |    60 | 17.0 |        
   45512 | 2024-04-15 19:04:59 |   MASTER-Kislovodsk | (14h 34m 42.40s , +71d 16m 12.0s) |   C |    60 | 17.8 |        
   45533 | 2024-04-15 19:05:20 |      MASTER-Tavrida | (11h 41m 07.92s , +78d 48m 47.3s) |   C |    60 | 18.6 |        
   45593 | 2024-04-15 19:06:20 |   MASTER-Kislovodsk | (14h 43m 17.06s , +79d 15m 58.1s) |   C |    60 | 17.1 |        
   45593 | 2024-04-15 19:06:20 |   MASTER-Kislovodsk | (15h 04m 49.15s , +78d 49m 00.0s) |   C |    60 | 17.8 |        
   45605 | 2024-04-15 19:06:32 |      MASTER-Tavrida | (12h 23m 34.35s , +78d 51m 09.5s) |   C |    60 | 18.6 |        
   45673 | 2024-04-15 19:07:40 |   MASTER-Kislovodsk | (14h 57m 50.89s , +75d 27m 52.6s) |   C |    60 | 17.0 |        
   45753 | 2024-04-15 19:09:00 |   MASTER-Kislovodsk | (13h 47m 36.20s , +69d 49m 09.2s) |   C |    60 | 17.1 |        
   45753 | 2024-04-15 19:09:00 |   MASTER-Kislovodsk | (13h 59m 42.52s , +69d 24m 28.3s) |   C |    60 | 17.8 |        
   45833 | 2024-04-15 19:10:20 |   MASTER-Kislovodsk | (14h 59m 12.52s , +80d 42m 48.6s) |   C |    60 | 17.8 |        
   45894 | 2024-04-15 19:11:22 |      MASTER-Tavrida | (12h 42m 08.42s , +75d 03m 32.5s) |   C |    60 | 18.6 |        
   45966 | 2024-04-15 19:12:33 |      MASTER-Tavrida | (13h 13m 51.27s , +75d 02m 51.3s) |   C |    60 | 18.6 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240414A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36120
SUBJECT: GRB 240414A: Fermi GBM Observation
DATE:    24/04/15 20:36:01 GMT
FROM:    Ava Myers at NASA GSFC <ava.myers@nasa.gov>

A. Myers (NPP/GSFC) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 02:20:39.26 UT on 14 April 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240414A (trigger 734754044/240414098).
which was also detected by Swift BAT (R. Caputo et al. 2024, GCN 36083).
The event was originally mislabeled as GRB 240414B 
(Fermi GBM Team, GCN 36612). The Fermi GBM on-ground 
location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight is 49 degrees.

The GBM light curve contains a double emission episode with a duration (T90)
of about 82 s (50-300 keV). The time-averaged spectrum
from T0-1.5 to T0+80.4 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.9 +/- 0.1 and the cutoff energy,
parameterized as Epeak, is 150 +/- 20 keV.

The event fluence (10-1000 keV) in this time interval is
(5.556 +/- 1.065)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.19 s in the 10-1000 keV band is 2.7 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB240415A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36121
SUBJECT: GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
DATE:    24/04/15 20:42:11 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Moskvitin (SAO RAS), S. Belkin (IKI) report on behalf of GRB-IKI-FuN:

We report correction to the GCN 36118 (Pankov et al.) and additional photometry in subsequent epochs.  
Preliminary photometry of the optical transient is following:

Date       UT_start  MJD           Filter Exp.  OT    err  UL(3sigma)
                    (mid, days)           (s)
2024-04-15 14:33:22  60415.627345  R     30*120 19.9 0.1 21.8
2024-04-15 16:13:49  60415.697104  R     30*120 20.5 0.1 21.9
2024-04-15 17:20:02  60415.732668  R     15*120 20.9 0.1 21.9

The magnitudes were calibrated using nearby USNO-B1.0 stars.


GRB_name: GRB240415A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36122
SUBJECT: GRB 240415A: SAO RAS optical observations
DATE:    24/04/15 21:04:13 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. Moskvitin, A. Vinokurov, A. Sarkisian (SAO RAS), N. Pankov (HSE, IKI),
A. Pozanenko (IKI), report on behalf of GRB follow-up team.

We observed the field of the GRB 240415A (Fermi GBM team, GCN 36107; Moss
et al., GCN 36108, Evans et al., GCN 36109) with the BTA, 6-m telescope of
SAO RAS, equipped with the Scorpio-2 multi-mode focal reducer (Afanasiev &
Moiseev,  2011, BaltA, 20, 363). We obtained series of 30 and 60 sec images
in VRI bands on April 15, 17:38:12--18:05:08 UT.

The OT (Pankov et al., GCNs 36118; 36121) is clearly detected in the
stacked frames of each band. Preliminary photometry of OT: R = 21.19 +/-
0.15 (17:39:08--18:03:53 UT, t_mid - T0 = 0.4754 days = 11.4104 hours). The
magnitudes were calibrated using R2 magnitudes of nearby USNO-B1.0 stars.


GRB_name: GRB240415A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36123
SUBJECT: GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
DATE:    24/04/15 21:17:04 GMT
FROM:    Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>

A. Reguitti (INAF-OAB / INAF-OAPd), P. D'Avanzo (INAF-OAB), L. Tomasella (INAF -OAPd), E. Cappellaro (INAF -OAPd), 
report on behalf of the CIBO and of the GRAWITA collaborations: 

We carried out follow-up optical observations of GRB 240415A (Fermi GBM Team, GCN Circ. #36107; Moss et al., GCN Circ. #36108) 
from the INAF - Padova Astronomical Observatory located in Asiago (Italy) with the 67/92 Schmidt telescope starting on 2024-04-15 at 19:13:10 UT 
(~ 12.8 hours after the burst) with the r-sdss filter.

In our stacked image the optical afterglow (Pankov et al., GCN Circ. #36118; Pankov et al., GCN Circ. #36121; Moskvitin et al., GCN Circ. #36122) 
is detected. 
From preliminary analysis we estimate a magnitude of r = 21.0 +/- 0.3 (AB; calibrated against r band of the PanSTARRS catalog).

Further observations are ongoing.


GRB_name: GRB240415A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36124
SUBJECT: GRB 240415A: OHP/T193 optical observations
DATE:    24/04/15 22:12:13 GMT
FROM:    Benjamin Schneider at MIT <bschn@mit.edu>

B. Schneider (MIT), C. Adami,  O. Ilbert, N. A. Rakotondrainibe (LAM/Pytheas/AMU), D. Turpin, E. Le Flocâ€™h (CEA Paris-Saclay), A. Saccardi, S. Vergani (GEPI/Obs. de Paris) report on behalf of a larger collaboration:

We observed the field of the GRB 240415A (Fermi GBM team, GCN 36107; Moss et al., GCN 36108; Evans et al., GCN 36109) and its afterglow candidate (Pankov et al., GCN 36118, GCN 36121; Moskvitin et al., GCN 36122; Reguitti et al., GCN 36123) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. A total of 6 exposures (5x600s + 1x480s) were obtained in the r-band at 20:37:17.5 UT on 2024-04-15 (~14.1h after the trigger). In the combined frame, we clearly detect the optical afterglow and measure the following preliminary magnitude:

r = 21.67 +/- 0.10 mag (AB)

The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitude is not corrected for Galactic extinction.

We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean Balcaen for the MISTRAL observations.


GRB_name: GRB240415B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36125
SUBJECT: GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
DATE:    24/04/15 22:22:56 GMT
FROM:    Jimmy DeLaunay at Penn State <delauj2@gmail.com>

James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC)  report:

Swift/BAT did not localize GRB 240415B onboard (T0: 2024-04-15T03:10:49.351 UTC, GECAM trigger 328).

The GECAM notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), detects the burst in a 0.256 s analysis time bin starting at T0 - 0.128 s with a sqrt(TS) of 16.2.
An arcminute localization is found with DeltaLLHOut of 26.8 and a DeltaLLHPeak of 9.4.

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

The BAT position is
RA, Dec = 132.317, -27.07 deg which is
   RA(J2000)  = 08h 49m 16.0s
   Dec(J2000) = -27d 04â€² 12.0â€³
with an estimated uncertainty of 5 arcmin radius.

Follow-up observations from other instruments are requested.
XRT and UVOT will not follow-up until March 18 due to planned observatory downtime.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB240415B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36126
SUBJECT: GRB 240415B: Swift/BAT-GUANO Correction 
DATE:    24/04/15 22:50:31 GMT
FROM:    Jimmy DeLaunay at Penn State <delauj2@gmail.com>

UVOT and XRT observations have been requested and approved. 


GRB_name: GRB240415B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36127
SUBJECT: GRB 240415B: Swift ToO observations
DATE:    24/04/15 23:25:14 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Swift/BAT GRB 240415B. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021683

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB240415A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36128
SUBJECT: GRB 240415A: Enhanced Swift-XRT position
DATE:    24/04/16 00:23:15 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 822 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 240415A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 129.18882, +73.14634 which is equivalent
to:

RA (J2000): 08h 36m 45.32s
Dec (J2000): +73d 08' 46.8"

with an uncertainty of 2.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB240414A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36131
SUBJECT: GRB 240414A: GMG observation
DATE:    24/04/16 06:54:24 GMT
FROM:    wangbaiting@ynao.ac.cn

B.-T. Wang, R.-Z. Li,  J. Mao, X.-L. Zhang, J.-M. Bai (YNAO) report:

We observed the field of GRB 240414A (Caputo et al. GCN 36083) by the GMG telescope in Yunnan observatories. The observation time began from UT 14:25:26.531  April 14, 2024, about 12 hours from the trigger. The preliminary results are shown as

----------------------------------------------------
UT    filter mag
----------------------------------------------------
2024-04-14T14:25:26.531  sdssr 20.6 Â± 0.3
----------------------------------------------------


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36133
SUBJECT: GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
DATE:    24/04/16 10:25:27 GMT
FROM:    Claudio Lopresti <cl3lop@gmail.com>

Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy)
Member of:
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section.
GAD - Gruppo Astronomia Digitale.

in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno), Unione Astrofili Italiani (UAI)

report:
We imaged the field of GRB 240414Adetected by SWIFT(trigger 1221714)
with the telescope LX200 12â€ of GAD Observatory, La Spezia, Italy

The observations started 1026 min after the GRB trigger,
with a Shmidt-Cassegrain telescope D=304 mm with reducer F/D=4.75.
at the following position (+/- 2 arcsec):

RA (J2000): 12h 19m 8.07s
Dec (J2000): +56d 44' 26.0"

scope D=300 mm F/D=4.8.

Weather conditions were medium.

The observation with a series of exposures started at 024-04-14 19:28:17 UT
and ended at 2024-04-14 22:27:10 UT

We co-added 88 exposures of 90 sec each.

Start T0+         End T0+        R lim
1026 min        1205 min      19,9

We did not found any optical counterpart in 12h 19m 8.07s +56d 44' 26.0" position and in the error box of the XRT  candidate.
ref.: K.L. Page at U Leicester GCN 36083

Magnitudes were estimated with the Gaia EDR3 cat. and
are not corrected for galactic dust extinction.

Reference:
https://www.parcodellestelle.com/

The message may be cited.


GRB_name: GRB240415A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36134
SUBJECT: GRB 240415A: Fermi GBM Observation
DATE:    24/04/16 10:26:05 GMT
FROM:    CuÃ¡n de Barra at UCD <cuan.debarra@ucdconnect.ie>

C. de Barra (UCD) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:

At 06:26:57.60 UT on 15 April 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240415A (trigger 734855222/240415269) which was also detected by Swift BAT (M.J. Moss et al. 2024, GCN 36108).

The Fermi GBM on-ground location (Fermi GBM Team, GCN 36107) is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 125.0 degrees

The GBM light curve contains a single emission episode with a duration (T90)
of about 10 s (50-300 keV). The time-averaged spectrum
from T0-4.1 to T0+6.1 s is best fit by is best fit by a Comptonized Epeak function with Epeak = 42.10 +/- 5.26 keV, and alpha = -1.58 +/- 0.14

The event fluence (10-1000 keV) in this time interval is (1.8 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.58 s in the 10-1000 keV band is 7.7 +/- 0.3 ph/s/cm^2. 

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/


GRB_name: GRB240415A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36136
SUBJECT: GRB 240415A: Swift/UVOT Detection
DATE:    24/04/16 13:38:30 GMT
FROM:    Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>

M. H. Siegel (PSU) and M. J. Moss (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240415A
3309 s after the BAT trigger (Moss et al., GCN Circ. 36108). A source consistent
with the XRT position (Beardmore et al., GCN Circ. 36128) and the reported
optical transient (Pankov et al., GCN Circ. 36118, Moskvitin et al., GCN Circ. 36122,
Reguitti et al., GCN Circ. 36123, Schneider et al., GCN Circ. 36124, Aryan et al.,
GCN Circ. 36132) is detected in the initial UVOT exposures.

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white             3877         4077          197         19.92 +/- 0.19
v                 4287         4487          197         18.95 +/- 0.28
b                 3672         3872          197        >19.2
u                 3467         5040          332         18.96 +/- 0.18
w1                4698         4897          197        >19.3
m2                4492         4692          197        >19.1
w2                4083         4282          197        >19.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.022 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB240414A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36137
SUBJECT: GRB 240414A: AbAO optical upprer limit
DATE:    24/04/16 14:12:25 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

N. Pankov (HSE, IKI), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI), 
S. Belkin (IKI) report on behalf of GRB-IKI-FuN:

We observed the field of GRB 240414A (Caputo et. al., GCN 36083) at 
redshift z=1.833 (Adami et al., GCN 36085; de Ugarte Postigo et al., GCN 36087) with 70-cm AS-32 telescope of Abastumani Observatory (AbAO). The observations were started on 2024-04-14 (UT) 22:06:33, i.e. ~20 hr since the Swift trigger. We took 117 frames 60 sec each in the R-filter. The optical counterpart (Schneider et al., GCN 36084; Adami et al., GCN 36085; de Ugarte Postigo et al., GCN 36087; Niwano et al., GCN 36088; Lipunov et al., GCN 36095; Dutton et al., GCN 36097; Peretto, GCN 36100; Turpin et al., GCN 36101; Karambelkar et al., GCN 36103; Odeh et al., GCN 36111; Pankov et al., GCN 36113; Siegel & Caputo, GCN 36115; de Ugarte Postigo et al., GCN 36117; Xiong et al., GCN 36130; Wang et al., GCN 36131; Lopresti et al., GCN 36133) is not detected in the stacked image of 113x60 sec. Preliminary photometry is following:

Date       UT_start  t-T0     Filter Exp.   OT    err  UL(3sigma)
                    (mid, days)      (s)
2024-04-14 22:06:33  0.86281  R      113*60 n/d   n.d  21.4

The magnitudes were calibrated with nearby USNO-B1.0 stars.

The result is in agreement with observations carried out by other groups, in particular, with (de Ugarte Postigo et al., GCN 36117) at the similar epoch.


GRB_name: GRB240414A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36140
SUBJECT: GRB 240414A: Swift-BAT refined analysis
DATE:    24/04/16 19:56:23 GMT
FROM:    Mike Moss at NASA GSFC <mikejmoss3@gmail.com>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
R. Caputo (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
M. J. Moss (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC), T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+199 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240414A (trigger #1221714)
(Caputo, et al., GCN Circ. 36083).  The BAT ground-calculated position is
RA, Dec = 184.781, 56.734 deg which is
   RA(J2000)  =  12h 19m 07.5s
   Dec(J2000) = +56d 44' 03.0"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.
 
The mask-weighted light curve shows multiple pulses starting at T0-35 s through
T0+40 s, with another pulse at T0+110 s. There may be additional emission prior 
to the currently available data starting from ~T0-61 s.
T90 (15-350 keV) is 88.28 +- 50.41 sec (estimated error including systematics).
 
The time-averaged spectrum from TTBD to TTBD sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.99 +- 0.36,
and Epeak of 97.0 +- 62.5 keV (chi squared 46.83 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.5 +- 0.2 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+2.04 sec in the 15-150 keV band is
1.5 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.49 +- 0.08 (chi squared 53.19 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.
 
The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1221714


GRB_name: GRB240411A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36141
SUBJECT: GRB 240411A: Glowbug gamma-ray detection
DATE:    24/04/16 21:12:57 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240411A, which was also detected by Fermi/GBM (GCN 36061), GRBAlpha (GCN 36068), as well as INTEGRAL/SPI-ACS, Swift/BAT, and Konus/Wind (GCN 36090).  
 
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-11 01:44:59.000 with a duration of 0.51 s and a total significance of about 25.8 sigma.  The light curve comprises a single peak.
 
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240415A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36143
SUBJECT: GRB 240415A: Swift-BAT refined analysis
DATE:    24/04/17 02:09:31 GMT
FROM:    Mike Moss at NASA GSFC <mikejmoss3@gmail.com>

M. J. Moss (GSFC), S. D. Barthelmy (GSFC), 
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC),
T. Sakamoto (AGU) (i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240415A (trigger #1221874)
(Moss, et al., GCN Circ. 36108).  The BAT ground-calculated position is
RA, Dec = 129.197, 73.150 deg which is 
   RA(J2000)  =  08h 36m 47.2s 
   Dec(J2000) = +73d 09' 01.7" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
 
The mask-weighted light curve displays a bright pulse lasting for ~15 s and 
peaking at ~T0+5 s and another dim pulse of emission at ~T0+30 s. 
The T90 (15-350 keV) is 30.96 +- 3.59 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.70 to T+37.50 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.28 +- 0.13.  The fluence in the 15-150 keV band is 1.6 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+5.09 sec in the 15-150 keV band
is 4.6 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1221874


GRB_name: GRB240414A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36147
SUBJECT: GRB 240414A: Glowbug gamma-ray detection
DATE:    24/04/17 14:54:25 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240414A, which was also detected by Swift/BAT (GCN 36083, 36140) and Fermi/GBM (GCN 36120).

The detection occurred during a time of high background, thus complicating the analysis. Using an adaptive window with a resolution of 32-ms, the primary peak was recovered, with a burst onset determined to be 2024-04-14 02:20:36.904 with a duration of 4.1 s and a total significance of about 9.7 sigma. Lower-level emission is observed up to ~T0+30s.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240415A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36148
SUBJECT: GRB 240415A: Glowbug gamma-ray detection
DATE:    24/04/17 14:55:09 GMT
FROM:    C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>

C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240415A, which was also detected by Fermi/GBM (GCN 36107, 36134) and Swift/BAT (GCN 36108, 36143).

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-15 06:26:52.488 with a duration of 8.2 s and a total significance of about 17.7 sigma.  The light curve comprises two primary peaks at ~T0+1s and ~T0+4s.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Programâ€™s STP-H9 to the ISS.  The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.


GRB_name: GRB240417A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36151
SUBJECT: GRB 240417A: Fermi GBM Final Real-time Localization
DATE:    24/04/17 18:56:42 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 18:46:10 UT on 17 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240417A (trigger 735072375.64676 / 240417782).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 30.7, Dec = -49.7 (J2000 degrees, equivalent to J2000 02h 02m, -49d 42'), with a statistical uncertainty of 12.8 degrees.

The angle from the Fermi LAT boresight is 133.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240417782/quicklook/glg_skymap_all_bn240417782.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240417782/quicklook/glg_healpix_all_bn240417782.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240417782/quicklook/glg_lc_medres34_bn240417782.gif


GRB_name: GRB240411A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36156
SUBJECT: Improved IPN triangulation of GRB 240411A
DATE:    24/04/18 10:47:24 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the MGNS/BepiColombo team,

J. Benkhoff on behalf of the BepiColombo team,

D. Svinkin, D. Frederiks,  A. Lysenko, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

Using the BepiColombo (MGNS) data we have improved
the previous IPN error box (Svinkin et al., GCN 36090).

The coordinates of the updated 3 sigma error box are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  248.823 (16h 35m 17s) +43.618 (+43d 37' 03")
 Corners:
  248.867 (16h 35m 28s) +43.236 (+43d 14' 08")
  248.814 (16h 35m 15s) +43.972 (+43d 58' 19")
  248.777 (16h 35m 07s) +43.999 (+43d 59' 57")
  248.831 (16h 35m 20s) +43.263 (+43d 15' 47")
 ---------------------------------------------
The error box area is 65 sq. arcmin, and its maximum
dimension is 46 arcmin (the minimum one is 1 arcmin).
The Sun distance was 111 deg.

This box may be further improved.

Updated triangulation map and HEALPix FITS files are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240411_T06302/IPN/


GRB_name: GRB240417A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36160
SUBJECT: Fermi GRB 240417A: Global MASTER-Net observations report
DATE:    24/04/18 15:15:59 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240417A ( Fermi GBM team, GCN 36151) errorbox  774 sec after notice time and 811 sec after trigger time at 2024-04-17 18:59:41 UT, with upper limit up to  18.2 mag. The observations began at zenith distance = 81 deg. The sun  altitude  is -35.5 deg. 

The galactic latitude b = -64 deg., longitude l = 276 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2425683

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     841 | 2024-04-17 18:59:41 |         MASTER-SAAO | (02h 19m 40.07s , -49d 59m 17.6s) |   C |    60 | 16.7 |        
     841 | 2024-04-17 18:59:41 |         MASTER-SAAO | (02h 22m 25.63s , -50d 12m 18.9s) |   C |    60 | 18.0 |        
     921 | 2024-04-17 19:01:01 |         MASTER-SAAO | (02h 25m 31.14s , -51d 54m 11.0s) |   C |    60 | 17.6 |        
     921 | 2024-04-17 19:01:01 |         MASTER-SAAO | (02h 28m 23.59s , -52d 07m 10.2s) |   C |    60 | 18.2 |        
    1001 | 2024-04-17 19:02:21 |         MASTER-SAAO | (02h 06m 24.22s , -53d 47m 21.4s) |   C |    60 | 17.3 |        
    1001 | 2024-04-17 19:02:21 |         MASTER-SAAO | (02h 09m 24.03s , -54d 00m 23.9s) |   C |    60 | 17.9 |        
    1081 | 2024-04-17 19:03:41 |         MASTER-SAAO | (02h 37m 07.92s , -48d 05m 50.6s) |   C |    60 | 17.1 |        
    1081 | 2024-04-17 19:03:41 |         MASTER-SAAO | (02h 39m 47.00s , -48d 18m 52.3s) |   C |    60 | 18.0 |        
    1161 | 2024-04-17 19:05:01 |         MASTER-SAAO | (02h 12m 39.18s , -55d 43m 14.3s) |   C |    60 | 17.7 |        
    1161 | 2024-04-17 19:05:01 |         MASTER-SAAO | (02h 15m 47.66s , -55d 56m 15.5s) |   C |    60 | 17.8 |        
    1240 | 2024-04-17 19:06:20 |         MASTER-SAAO | (02h 32m 17.11s , -53d 48m 54.6s) |   C |    60 | 17.8 |        
    1240 | 2024-04-17 19:06:20 |         MASTER-SAAO | (02h 35m 16.99s , -54d 01m 54.5s) |   C |    60 | 18.1 |        
    1320 | 2024-04-17 19:07:40 |         MASTER-SAAO | (02h 43m 18.37s , -49d 59m 03.5s) |   C |    60 | 17.6 |        
    1320 | 2024-04-17 19:07:40 |         MASTER-SAAO | (02h 46m 03.49s , -50d 12m 05.0s) |   C |    60 | 18.1 |        
    1399 | 2024-04-17 19:09:00 |         MASTER-SAAO | (02h 50m 14.83s , -51d 54m 15.6s) |   C |    60 | 17.9 |        
    1399 | 2024-04-17 19:09:00 |         MASTER-SAAO | (02h 53m 06.96s , -52d 07m 15.0s) |   C |    60 | 18.1 |        
    1479 | 2024-04-17 19:10:19 |         MASTER-SAAO | (02h 39m 45.84s , -55d 41m 02.2s) |   C |    60 | 17.9 |        
    1479 | 2024-04-17 19:10:19 |         MASTER-SAAO | (02h 42m 54.28s , -55d 54m 01.9s) |   C |    60 | 18.1 |        
    2049 | 2024-04-17 19:19:50 |         MASTER-SAAO | (02h 19m 50.95s , -57d 36m 10.4s) |   C |    60 | 17.6 |        
    2049 | 2024-04-17 19:19:50 |         MASTER-SAAO | (02h 23m 09.63s , -57d 49m 11.0s) |   C |    60 | 18.0 |        
    2129 | 2024-04-17 19:21:09 |         MASTER-SAAO | (02h 12m 43.89s , -55d 43m 12.1s) |   C |    60 | 17.4 |        
    2129 | 2024-04-17 19:21:09 |         MASTER-SAAO | (02h 15m 52.54s , -55d 56m 16.3s) |   C |    60 | 17.7 |        
    2209 | 2024-04-17 19:22:29 |         MASTER-SAAO | (02h 32m 20.62s , -53d 48m 34.2s) |   C |    60 | 17.4 |        
    2209 | 2024-04-17 19:22:29 |         MASTER-SAAO | (02h 35m 20.64s , -54d 01m 37.3s) |   C |    60 | 18.0 |        
    2289 | 2024-04-17 19:23:49 |         MASTER-SAAO | (02h 58m 03.34s , -53d 47m 56.0s) |   C |    60 | 17.7 |        
    2289 | 2024-04-17 19:23:49 |         MASTER-SAAO | (03h 01m 03.63s , -54d 00m 55.3s) |   C |    60 | 17.8 |        
    2368 | 2024-04-17 19:25:09 |         MASTER-SAAO | (02h 50m 21.71s , -51d 52m 51.9s) |   C |    60 | 17.5 |        
    2368 | 2024-04-17 19:25:09 |         MASTER-SAAO | (02h 53m 13.93s , -52d 05m 54.1s) |   C |    60 | 17.9 |        
    2448 | 2024-04-17 19:26:28 |         MASTER-SAAO | (02h 39m 43.88s , -55d 41m 38.1s) |   C |    60 | 17.6 |        
    2448 | 2024-04-17 19:26:28 |         MASTER-SAAO | (02h 42m 52.44s , -55d 54m 40.0s) |   C |    60 | 18.0 |        
    2528 | 2024-04-17 19:27:48 |         MASTER-SAAO | (02h 59m 53.48s , -48d 04m 10.7s) |   C |    60 | 17.1 |        
    2528 | 2024-04-17 19:27:48 |         MASTER-SAAO | (03h 02m 32.38s , -48d 17m 15.3s) |   C |    60 | 18.0 |        
    2608 | 2024-04-17 19:29:08 |         MASTER-SAAO | (03h 07m 05.82s , -49d 59m 07.5s) |   C |    60 | 17.4 |        
    2608 | 2024-04-17 19:29:08 |         MASTER-SAAO | (03h 09m 51.00s , -50d 12m 09.4s) |   C |    60 | 18.1 |        
    2688 | 2024-04-17 19:30:28 |         MASTER-SAAO | (01h 57m 51.98s , -59d 31m 22.7s) |   C |    60 | 17.7 |        
    2688 | 2024-04-17 19:30:28 |         MASTER-SAAO | (02h 01m 20.89s , -59d 44m 30.9s) |   C |    60 | 17.9 |        
    2767 | 2024-04-17 19:31:47 |         MASTER-SAAO | (02h 48m 18.36s , -57d 36m 03.2s) |   C |    60 | 17.7 |        
    2767 | 2024-04-17 19:31:47 |         MASTER-SAAO | (02h 51m 36.68s , -57d 49m 04.8s) |   C |    60 | 17.8 |        
    2847 | 2024-04-17 19:33:07 |         MASTER-SAAO | (02h 27m 51.47s , -59d 28m 57.3s) |   C |    60 | 17.9 |        
    2847 | 2024-04-17 19:33:07 |         MASTER-SAAO | (02h 31m 20.55s , -59d 42m 00.7s) |   C |    60 | 18.1 |        
    3026 | 2024-04-17 19:36:06 |         MASTER-SAAO | (02h 19m 50.18s , -57d 36m 53.1s) |   C |    60 | 17.6 |        
    3026 | 2024-04-17 19:36:06 |         MASTER-SAAO | (02h 23m 08.30s , -57d 49m 58.3s) |   C |    60 | 17.9 |        
    3106 | 2024-04-17 19:37:26 |         MASTER-SAAO | (03h 06m 49.57s , -55d 40m 25.7s) |   C |    60 | 17.7 |        
    3106 | 2024-04-17 19:37:26 |         MASTER-SAAO | (03h 09m 58.14s , -55d 53m 25.1s) |   C |    60 | 17.9 |        
    3186 | 2024-04-17 19:38:46 |         MASTER-SAAO | (03h 15m 03.12s , -51d 52m 17.0s) |   C |    60 | 17.6 |        
    3186 | 2024-04-17 19:38:46 |         MASTER-SAAO | (03h 17m 55.06s , -52d 05m 17.5s) |   C |    60 | 17.9 |        
    3266 | 2024-04-17 19:40:06 |         MASTER-SAAO | (02h 58m 04.42s , -53d 46m 10.0s) |   C |    60 | 17.4 |        
    3266 | 2024-04-17 19:40:06 |         MASTER-SAAO | (03h 01m 03.86s , -53d 59m 12.9s) |   C |    60 | 17.6 |        
    3346 | 2024-04-17 19:41:26 |         MASTER-SAAO | (02h 05m 15.46s , -61d 25m 16.1s) |   C |    60 | 17.7 |        
    3346 | 2024-04-17 19:41:26 |         MASTER-SAAO | (02h 08m 56.84s , -61d 38m 22.5s) |   C |    60 | 18.0 |        
    3426 | 2024-04-17 19:42:46 |         MASTER-SAAO | (02h 39m 54.65s , -55d 42m 06.4s) |   C |    60 | 17.5 |        
    3426 | 2024-04-17 19:42:46 |         MASTER-SAAO | (02h 43m 02.68s , -55d 55m 12.1s) |   C |    60 | 17.9 |        
    3505 | 2024-04-17 19:44:06 |         MASTER-SAAO | (02h 57m 52.33s , -59d 29m 44.7s) |   C |    60 | 17.8 |        
    3506 | 2024-04-17 19:44:06 |         MASTER-SAAO | (03h 01m 21.54s , -59d 42m 45.4s) |   C |    60 | 18.0 |        
    3681 | 2024-04-17 19:47:01 |         MASTER-SAAO | (02h 48m 21.96s , -57d 35m 18.3s) |   C |    60 | 17.5 |        
    3681 | 2024-04-17 19:47:01 |         MASTER-SAAO | (02h 51m 40.07s , -57d 48m 21.0s) |   C |    60 | 17.8 |        
    3760 | 2024-04-17 19:48:21 |         MASTER-SAAO | (02h 27m 54.17s , -59d 30m 45.3s) |   C |    60 | 17.5 |        
    3760 | 2024-04-17 19:48:21 |         MASTER-SAAO | (02h 31m 23.18s , -59d 43m 50.1s) |   C |    60 | 17.8 |        
    3840 | 2024-04-17 19:49:40 |         MASTER-SAAO | (02h 37m 08.32s , -61d 24m 32.3s) |   C |    60 | 17.7 |        
    3840 | 2024-04-17 19:49:40 |         MASTER-SAAO | (02h 40m 50.22s , -61d 37m 34.9s) |   C |    60 | 17.8 |        
    3920 | 2024-04-17 19:51:00 |         MASTER-SAAO | (03h 23m 55.07s , -53d 47m 16.4s) |   C |    60 | 17.6 |        
    3920 | 2024-04-17 19:51:00 |         MASTER-SAAO | (03h 26m 54.82s , -54d 00m 16.9s) |   C |    60 | 17.6 |        
    3999 | 2024-04-17 19:52:19 |         MASTER-SAAO | (03h 16m 46.82s , -57d 34m 09.9s) |   C |    60 | 17.5 |        
    3999 | 2024-04-17 19:52:19 |         MASTER-SAAO | (03h 20m 04.98s , -57d 47m 09.9s) |   C |    60 | 17.7 |        
    4079 | 2024-04-17 19:53:39 |         MASTER-SAAO | (03h 06m 50.03s , -55d 40m 54.8s) |   C |    60 | 17.4 |        
    4079 | 2024-04-17 19:53:39 |         MASTER-SAAO | (03h 09m 58.28s , -55d 53m 57.4s) |   C |    60 | 17.7 |        
    4158 | 2024-04-17 19:54:59 |         MASTER-SAAO | (03h 15m 00.23s , -51d 51m 42.3s) |   C |    60 | 14.3 |        
    4158 | 2024-04-17 19:54:59 |         MASTER-SAAO | (03h 17m 51.89s , -52d 04m 46.8s) |   C |    60 | 15.1 |        
    4238 | 2024-04-17 19:56:18 |         MASTER-SAAO | (02h 58m 15.68s , -53d 47m 01.1s) |   C |    60 | 16.3 |        
    4238 | 2024-04-17 19:56:18 |         MASTER-SAAO | (03h 01m 15.00s , -54d 00m 08.3s) |   C |    60 | 16.6 |        
    4318 | 2024-04-17 19:57:38 |         MASTER-SAAO | (02h 05m 23.14s , -61d 25m 20.2s) |   C |    60 | 16.1 |        
    4318 | 2024-04-17 19:57:38 |         MASTER-SAAO | (02h 09m 04.28s , -61d 38m 30.0s) |   C |    60 | 16.6 |        
    4398 | 2024-04-17 19:58:58 |         MASTER-SAAO | (02h 13m 52.27s , -63d 18m 45.2s) |   C |    60 | 17.4 |        
    4398 | 2024-04-17 19:58:58 |         MASTER-SAAO | (02h 17m 48.14s , -63d 31m 52.1s) |   C |    60 | 17.6 |        
    4478 | 2024-04-17 20:00:18 |         MASTER-SAAO | (02h 57m 58.29s , -59d 29m 40.0s) |   C |    60 | 15.1 |        
    4478 | 2024-04-17 20:00:18 |         MASTER-SAAO | (03h 01m 27.24s , -59d 42m 43.2s) |   C |    60 | 15.9 |        
    4576 | 2024-04-17 20:01:56 |         MASTER-SAAO | (01h 40m 22.93s , -63d 29m 31.1s) |   C |    60 | 16.5 |        
    4576 | 2024-04-17 20:01:56 |         MASTER-SAAO | (01h 36m 52.94s , -63d 16m 04.8s) |   C |    60 | 16.1 |        
    4668 | 2024-04-17 20:03:28 |         MASTER-SAAO | (02h 48m 31.38s , -57d 35m 15.9s) |   C |    60 | 16.8 |        
    4668 | 2024-04-17 20:03:28 |         MASTER-SAAO | (02h 51m 45.99s , -57d 48m 17.9s) |   C |    60 | 17.2 |        
    4748 | 2024-04-17 20:04:48 |         MASTER-SAAO | (03h 30m 49.13s , -49d 59m 18.4s) |   C |    60 | 14.4 |        
    4748 | 2024-04-17 20:04:48 |         MASTER-SAAO | (03h 33m 31.29s , -50d 12m 19.1s) |   C |    60 | 16.2 |        
    5251 | 2024-04-17 20:13:11 |         MASTER-SAAO | (02h 37m 21.09s , -61d 23m 37.4s) |   C |    60 | 14.3 |        
    5251 | 2024-04-17 20:13:11 |         MASTER-SAAO | (02h 40m 58.78s , -61d 36m 39.4s) |   C |    60 | 15.0 |        
    5331 | 2024-04-17 20:14:31 |         MASTER-SAAO | (03h 24m 00.11s , -53d 47m 23.3s) |   C |    60 | 15.2 |        
    5331 | 2024-04-17 20:14:31 |         MASTER-SAAO | (03h 26m 56.37s , -54d 00m 25.0s) |   C |    60 | 15.9 |        
    5410 | 2024-04-17 20:15:51 |         MASTER-SAAO | (03h 16m 56.49s , -57d 35m 08.1s) |   C |    60 | 16.6 |        
    5410 | 2024-04-17 20:15:51 |         MASTER-SAAO | (03h 20m 10.64s , -57d 48m 08.3s) |   C |    60 | 16.7 |        
    5510 | 2024-04-17 20:17:30 |         MASTER-SAAO | (03h 07m 04.39s , -55d 39m 51.6s) |   C |    60 | 16.6 |        
    5510 | 2024-04-17 20:17:30 |         MASTER-SAAO | (03h 10m 08.60s , -55d 52m 56.1s) |   C |    60 | 16.9 |        
    5590 | 2024-04-17 20:18:50 |         MASTER-SAAO | (02h 14m 02.20s , -63d 18m 18.2s) |   C |    60 | 13.0 |        
    5590 | 2024-04-17 20:18:50 |         MASTER-SAAO | (02h 17m 53.23s , -63d 31m 28.1s) |   C |    60 | 14.1 |        
    5669 | 2024-04-17 20:20:09 |         MASTER-SAAO | (02h 58m 06.27s , -59d 27m 57.6s) |   C |    60 | 16.4 |        
    5669 | 2024-04-17 20:20:09 |         MASTER-SAAO | (03h 01m 30.82s , -59d 41m 04.8s) |   C |    60 | 16.6 |        
    6169 | 2024-04-17 20:28:30 |         MASTER-SAAO | (02h 37m 24.10s , -61d 22m 39.0s) |   C |    60 | 12.7 |        
    6169 | 2024-04-17 20:28:30 |         MASTER-SAAO | (02h 41m 01.66s , -61d 35m 49.8s) |   C |    60 | 13.2 |        
    6593 | 2024-04-17 20:35:33 |         MASTER-SAAO | (03h 17m 04.62s , -57d 33m 41.0s) |   C |    60 | 17.3 |        
    6593 | 2024-04-17 20:35:33 |         MASTER-SAAO | (03h 20m 18.38s , -57d 46m 44.5s) |   C |    60 | 17.6 |        
    6685 | 2024-04-17 20:37:05 |         MASTER-SAAO | (02h 14m 27.70s , -63d 28m 51.0s) |   C |    60 | 17.1 |        
    6685 | 2024-04-17 20:37:05 |         MASTER-SAAO | (02h 10m 56.62s , -63d 15m 23.0s) |   C |    60 | 16.8 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB240418A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36162
SUBJECT: GRB 240418A: Swift detection of a burst
DATE:    24/04/18 20:36:44 GMT
FROM:    Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>


M. H. Siegel (PSU), S. Dichiara (PSU), J.D. Gropp (PSU),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and
M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 20:24:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240418A (trigger=1222885).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 239.322, +23.607 which is 
   RA(J2000) = 15h 57m 17s
   Dec(J2000) = +23d 36' 26"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of at least 20 sec.  The peak count rate
was ~700 counts/sec (15-350 keV), at ~7 sec after the trigger. 

The XRT began observing the field at 20:26:10.4 UT, 122.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 239.37228, 23.59581 which is equivalent
to:
   RA(J2000)  = 15h 57m 29.35s
   Dec(J2000) = +23d 35' 44.9"
with an uncertainty of 6.5 arcseconds (radius, 90% containment). This
location is 170 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
https://www.swift.ac.uk/sper.  We cannot determine whether the source
is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.26
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 125 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.058. 

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB240411A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  36164
SUBJECT: GRB 240411A: GOTO early optical upper limits
DATE:    24/04/18 20:43:43 GMT
FROM:    Ben Gompertz at U of Birmingham <b.gompertz@bham.ac.uk>

B. P. Gompertz, D. Steeghs, B. Godson; R. Starling, K. Ackley; M. J. Dyer; J. Lyman; K. Ulaczyk; F. Jimenez-Ibarra; A. Kumar; D. O'Neill; D. K. Galloway; V. Dhillon; P. O'Brien; G. Ramsay; K. Noysena; R. Kotak; R. P. Breton; L. K. Nuttall; E. Pall'e and D. Pollacco report on behalf of the GOTO collaboration:

We report on observations with the Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022) in response to GRB 240411A (Fermi GBM Team, GCN 36061; Pal et al., GCN 36068; Cheung et al., 36141). Targeted observations began at 01:57:29 UT on 2024-04-11, 12 minutes after the GBM trigger. Each observation consisted of 4x90s exposures in the GOTO L-band (400-700 nm).

Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using recent survey observations of the same pointings. Source candidates were initially filtered using a classifier (Killestein et al. 2021) and cross-matched against a variety of contextual and minor planet catalogues. Human vetting was carried out in real time on any candidates that passed the above checks.

No new candidate transient events are identified within the refined IPN error box (Kozyrev et al., GCN 36156). The 5-sigma limiting magnitude of the image is L > 19.7 at 12 minutes after trigger.

Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction.

GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC).


