# GCN_circulars

GRB_name: GRB220730A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32431
SUBJECT: GRB 220730A: Swift detection of a short hard burst
DATE:    22/07/30 16:05:05 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. Dichiara (PSU), J. A. Kennea (PSU),
N. J. Klingler (GSFC/UMBC/CRESSTII), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
A. Tohuvavohu (U Toronto) and M. A. Williams (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 15:48:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220730A (trigger=1118357).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 225.021, -69.497 which is 
   RA(J2000) = 15h 00m 05s
   Dec(J2000) = -69d 29' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single spike
structure with a duration of about 0.2 sec.  The peak count rate
was ~10000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 15:50:43.0 UT, 108.2 seconds after
the BAT trigger. No source was detected in 446 s of promptly downlinked
data. We are waiting for the full dataset to detect and localise the
XRT counterpart. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 111 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 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 91% of the
BAT 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
0.161. 

Burst Advocate for this burst is S. Dichiara (simonedichiara55 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: GRB220730A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32432
SUBJECT: Swift GRB 220730A: Global MASTER-Net observations report 
DATE:    22/07/30 17:00:18 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220730A ( S. Dichiara et al., GCN 32431) errorbox  3555 sec after notice time and 3568 sec after trigger time at 2022-07-30 16:48:23 UT, with upper limit up to  17.7 mag. Observations started at twilight.  The observations began at zenith distance = 38 deg. The sun  altitude  is -10.3 deg. 

The galactic latitude b = -10 deg., longitude l = 314 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2044932

We obtain a following upper limits.  

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

    3659 |         MASTER-SAAO |   C |   180 | 17.4 |        
    3870 |         MASTER-SAAO |   C |   180 | 17.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220729A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32433
SUBJECT: GRB 220729A: AstroSat CZTI detection
DATE:    22/07/31 06:02:37 GMT
FROM:    Varun Bhalerao at Indian Inst of Tech  <varunb@iitb.ac.in>

R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A. Suresh (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 GRB 220729A which was also detected by Fermi GBM (TrigNum: 680782656).

The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2022-07-29 10:17:31.550 UTC. The measured peak count rate associated with the burst is 556 (+159, -157) counts/s above the background in the combined data of all quadrants, with a total of 145 (+54, -58) counts. The local mean background count rate was 455 (+9, -12) counts/s. Using cumulative rates, we measure a T90 of 0.63 (+0.22, -0.42) s.

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


GRB_name: GRB220730A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32434
SUBJECT: GRB 220730A: Swift-XRT observations
DATE:    22/07/31 16:16:31 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and S. Dichiara (PSU)
report on behalf of the Swift-XRT team:

We have analysed 5.7 ks of Photon Counting (PC) mode XRT data for the
Swift-BAT-detected burst GRB 220730A (Dichiara et al. GCN Circ. 32431),
collected between T0+3.8 ks and T0+51.6 ks. 

Four uncatalogued X-ray sources have been detected consistent with
being within 296 arcsec of the Swift-BAT position, however none of them
is above the RASS limit or shows definitive signs of fading. Therefore,
at the present time we cannot identify which, if any, is the afterglow.
Details of these sources are given below:

Source 1:
  RA (J2000):  224.9153  =  14:59:39.66
  Dec (J2000): -69.5540  =  -69:33:14.4
  Error: 6.4 arcsec (radius, 90% conf.)
  Count-rate: (1.27 [+0.69, -0.53])e-3 ct s^-1  
  Distance: 244 arcsec from Swift-BAT position.
  Flux: (4.0 [+2.2, -1.7])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 5:
  RA (J2000):  225.0143  =  15:00:3.43
  Dec (J2000): -69.4959  =  -69:29:45.4
  Error: 6.6 arcsec (radius, 90% conf.)
  Count-rate: (1.90 [+1.02, -0.77])e-3 ct s^-1  
  Distance: 9 arcsec from Swift-BAT position.
  Flux: (4.0 [+2.2, -1.6])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 7:
  RA (J2000):  225.0749  =  15:00:17.98
  Dec (J2000): -69.4908  =  -69:29:26.9
  Error: 7.3 arcsec (radius, 90% conf.)
  Count-rate: (1.68 [+0.79, -0.62])e-3 ct s^-1  
  Distance: 71 arcsec from Swift-BAT position.
  Flux: (1.12 [+0.53, -0.41])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 8:
  RA (J2000):  224.9654  =  14:59:51.71
  Dec (J2000): -69.5389  =  -69:32:20.2
  Error: 7.4 arcsec (radius, 90% conf.)
  Count-rate: (2.53 [+0.93, -0.76])e-3 ct s^-1  
  Distance: 166 arcsec from Swift-BAT position.
  Flux: (3.13 [+1.15, -0.94])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Five uncatalogued sources were also detected too far from the GRB
position to be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/01118357.

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


GRB_name: GRB220730A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32435
SUBJECT: GRB 220730A: Swift/UVOT Upper Limits
DATE:    22/08/01 11:50:57 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and S. Dichiara (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220730A
112 s after the BAT trigger (Dichiara et al., GCN Circ. 32431).
No optical afterglow consistent with any of the positions in GCN Circ.
32434 (D'Ai et al.) has been detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           112          261          147         >20.5
u_FC               324          574          246         >19.8
white              112          623          167         >20.6
v                  655          675           19         >17.8
b                  579          599           19         >18.7
u                  324          574          246         >19.8
w2                 630          650           19         >18.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.161 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB220730A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32436
SUBJECT: GRB 220730A: Swift-XRT afterglow detection
DATE:    22/08/01 14:07:50 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. Dichiara (PSU), A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D.
Gropp (PSU), J.A. Kennea (PSU), K.L. Page (U. Leicester), A.P.
Beardmore (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato
(INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
Swift-BAT-detected burst GRB 220730A (Dichiara et al. GCN Circ. 32431).
The observations now extend from T0+119 s to T0+124.8 ks. 

Of the sources reported by D'Ai et al. (GCN Circ. 32434), "Source 5" is
fading with >3-sigma significance and is believed to be the afterglow. 
The position of this source is RA, Dec=225.0143, -69.4959 which is
equivalent to:

RA (J2000): 15:00:3.43
Dec(J2000): -69:29:45.4

with an uncertainty of 6.6 arcsec (radius, 90% confidence).  This
position is 9.3 arcsec from the Swift-BAT position.  

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01118357.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/01118357.

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


GRB_name: GRB220730A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32437
SUBJECT: GRB 220730A: Fermi GBM detection
DATE:    22/08/02 15:36:47 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076@uah.edu>

S. Poolakkil (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 15:48:55.032 UT on 30 July 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220730A (trigger 680888940 / 220730659)
which was also detected by the Swift/BAT (Dichiara et al. 2022, GCN 32431).

The angle from the Fermi LAT boresight at the GBM trigger time is 121
degrees.

The GBM light curve consists of a single peak followed
by some extended emission with a duration (T90) of about 0.16 s (50-300
keV).
The time-averaged spectrum from T0-0.064 s to T0+0.192 s
is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.34 +/- 0.18  and
the cutoff energy, parameterized as Epeak, is 488 +/- 84 keV.
A Band function fits equally well, with Epeak = 412 +/- 97 keV,
alpha = -0.21 +/- 0.25 and beta = -2.47 +/- 0.68.

The event fluence (10-1000 keV) in this time interval is
(1.06 +/- 0.09)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0 s in the 10-1000 keV band
is 24.9 +/- 2.2 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: GRB220730A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32438
SUBJECT: GRB 220730A: Swift-BAT refined analysis
DATE:    22/08/02 15:40:32 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), S. Dichiara (PSU),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+700 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220730A (trigger #1118357)
(Dichiara, et al., GCN Circ. 32431).  The BAT ground-calculated position is
RA, Dec = 224.988, -69.496 deg which is
   RA(J2000)  =  14h 59m 57.1s
   Dec(J2000) = -69d 29' 44.5"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
The mask-weighted light curve shows a single FRED-shaped pulse from
approximately T-0.05 to T+0.25 seconds. T90 (15-350 keV) is 0.19 +- 0.20 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.04 to T+0.28 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.61 +- 0.25.  The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.35 sec in the 15-150 keV band
is 1.6 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1118357/BA/


GRB_name: GRB220730A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32439
SUBJECT: Konus-Wind detection of GRB 220730A (short)
DATE:    22/08/02 16:48:45 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 220730A (Swift detection: Dichiara et al., GCN Circ 32431;
Swift-BAT refined analysis: Markwardt et al., GCN Circ 32438;
Fermi GBM detection:  Poolakkil & Meegan, GCN Circ 32437)
triggered Konus-Wind (KW) at T0=56937.381 s UT (15:48:57.381).

The burst light curve shows a single emission pulse
which starts at ~T0-0.032 s and has a duration of ~0.1 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/GRB220730_T56937/

As observed by Konus-Wind, the burst had
a total fluence of (1.20 Â± 0.38)x10^-6 erg/cm^2 and
a 16-ms peak energy flux, measured from T0,
of (1.62 Â± 0.51)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.064 s)
is best fit in the 20 keV - 15 MeV range by a power law with exponential
cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.14(-0.34,+0.40) and Ep = 369(-59,+92) keV (pgstat = 50/54 dof).
A Band function fits the spectrum equally well with alpha = -0.08 (-0.36,+0.42),
beta = -2.61(-1.33, + 0.45), and Ep = 347 (-54, +86) keV (pgstat = 48/53 dof).


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


GRB_name: GRB220803A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32441
SUBJECT: GRB 220803A: AstroSat CZTI detection
DATE:    22/08/04 11:25:47 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

R. Gopalakrishnan (IUCAA), V. Prasad (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 GRB 220803A which was also 
detected by Fermi-GBM (TrigNum: 681212354) and was reported in an 
IPN_RAW Notice (contributed by Konus-Wind).

The source was clearly detected in the 20-200 keV energy range. The 
light curve showed multiple peaks of emission with the strongest peak at 
2022-08-03 09:39:10.15 UTC. The measured peak count rate associated with 
the burst is 714 (+175, -87) counts/s above the background in the 
combined data of three (out of four) quadrants, with a total of 935 
(+238, -226) counts. The local mean background count rate was 349 (+5, 
-6) counts/s. Using cumulative rates, we measure a T90 of 3.9 (+4.3, 
-1.0) s.

It was also clearly detected in the CsI anticoincidence (Veto) detector 
in the 100-500 keV energy range. The light curve peaks at 2022-08-03 
09:39:09.32 UTC. The measured peak count rate is 274 (+72, -76) counts/s 
above the background in the combined Veto data of all quadrants, with a 
total of 842 (+310, -330) counts. The local mean background count rate 
was 1691 (+8, -9) counts/s. We measure a T90 of 6 (+2, -4) s from the 
cumulative Veto light curve.

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


GRB_name: GRB220804A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32443
SUBJECT: GRB 220804A: Fermi GBM Final Localization
DATE:    22/08/04 20:45:16 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

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

At 02:08:32.77 UT on 4 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220804A (trigger 681271717 / 220804089).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 159.4, Dec = 9.4 (J2000 degrees, equivalent to J2000 10h 38m, +9d 24'), with a statistical uncertainty of 6.5 degrees.

The angle from the Fermi LAT boresight is 81.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220804089/quicklook/glg_skymap_all_bn220804089.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220804089/quicklook/glg_healpix_all_bn220804089.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220804089/quicklook/glg_lc_medres34_bn220804089.gif


GRB_name: GRB220806A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32445
SUBJECT: GRB 220806A: Swift detection of a burst
DATE:    22/08/06 18:17:18 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. L. Page (U Leicester), J.D. Gropp (PSU), S. Laha (GSFC/UMBC),
D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 18:08:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220806A (trigger=1119268).  Swift could not slew to the
burst location due to a Moon constraint. 
The BAT on-board calculated location is 
RA, Dec 260.873, -26.023 which is 
   RA(J2000) = 17h 23m 30s
   Dec(J2000) = -26d 01' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 5 sec.  The peak count rate
was ~1700 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 18:30 UT on 2022 August 09. There will thus be no XRT or
UVOT data for this trigger before this time. 

Burst Advocate for this burst is K. L. Page (kimlpage1978 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: GRB220806A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32453
SUBJECT: GRB 220806A: Swift-BAT refined analysis
DATE:    22/08/09 21:27:59 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha@nasa.gov>

D. M. Palmer (LANL),S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (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 220806A (trigger #1119268)
(Page et al., GCN Circ. 32445).  The BAT ground-calculated position is
RA, Dec = 260.858, -26.021 deg which is
   RA(J2000)  =  17h 23m 26.0s
   Dec(J2000) = -26d 01' 15.2"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The BAT light curve showed a single peaked structure with a duration of about 6 sec.
T90 (15-350 keV) is 4.78 +- 2.00 sec (estimated error including systematics).

The time-averaged spectrum from T-0.30 to T+6.66 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.81 +- 0.33.  The fluence in the 15-150 keV band is 1.5 +- 0.3 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.76 sec in the 15-150 keV band
is 1.1 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1119268/BA/


GRB_name: GRB220627A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32454
SUBJECT: GRB 220627A: MeerKAT radio observations
DATE:    22/08/10 16:47:21 GMT
FROM:    Stefano Giarratana at University of Bologna  <s.giarratana@ira.inaf.it>

S. Giarratana (U. Bologna, INAF/IRA), J. Leung (U. Sydney, CSIRO),
Z. Wang (U. Sydney, CSIRO), T. An (SHAO), A. Deller (Swinburne),
G. Ghirlanda (INAF/Brera), M. Giroletti (INAF/IRA), D. L. Kaplan (UWM),
E. Lenc (CSIRO), T. Murphy (U. Sydney), L. Rhodes (U. Oxford),
O. S. Salafia (U. Milano-Bicocca, INAF/Brera), C. Spingola (INAF/IRA)

The MeerKAT radio telescope observed GRB 220627A (Fermi GBM team, GCN 
32278;
Frederiks et al., GCN 32295; Suresh et al., GCN 32316) at a central 
frequency
of 1.28 GHz, with a bandwidth of 0.78 GHz, over two epochs, starting at
18:44 UT on 2022 July 6 (8.9 days post-burst) and at 13:43 UT on 2022 
August 2
(35.7 days post-burst). Each observation lasted 2 hours.

 From our preliminary analysis, no source is detected with a >3 sigma
significance at a position consistent with previous detections
(de Wet et al., GCN 32289; Izzo et al., GCN 32291; Gropp et al., GCN 
32296;
Nicuesa Guelbenzu et al., GCN 32304; Leung et al., GCN 32341).

The rms noise is approximately 9 and 14 uJy/beam, in the first and 
second
epoch, respectively.

Further observations are planned.

We would like to thank the MeerKAT personnel for approving, executing,
and processing these observations.

The MeerKAT telescope is operated by the South African Radio Astronomy
Observatory, which is a facility of the National Research Foundation,
an agency of the Department of Science and Innovation.


GRB_name: GRB220810A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32455
SUBJECT: GRB 220810A: Fermi GBM Final Real-time Localization
DATE:    22/08/10 23:26:25 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 23:15:42 UT on 10 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220810A (trigger 681866147.080906 / 220810969).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 309.4, Dec = 2.7 (J2000 degrees, equivalent to J2000 20h 37m, 2d 42'), with a statistical uncertainty of 1.6 degrees.

The angle from the Fermi LAT boresight is 69.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220810969/quicklook/glg_skymap_all_bn220810969.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220810969/quicklook/glg_healpix_all_bn220810969.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220810969/quicklook/glg_lc_medres34_bn220810969.gif


GRB_name: GRB220810A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32456
SUBJECT: Fermi GRB 220810A: Global MASTER-Net observations report 
DATE:    22/08/11 00:15:15 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220810A ( Fermi GBM team, GCN 32455) errorbox  445 sec after notice time and 476 sec after trigger time at 2022-08-10 23:23:38 UT, with upper limit up to  18.3 mag. The observations began at zenith distance = 39 deg. The sun  altitude  is -71.2 deg. 

The galactic latitude b = -22 deg., longitude l = 49 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2053838

We obtain a following upper limits.  

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

     521 | 2022-08-10 23:23:38 |         MASTER-SAAO | (20h 45m 02.76s , +02d 31m 33.6s) |   C |    90 | 17.6 |        
     656 | 2022-08-10 23:25:37 |         MASTER-SAAO | (20h 36m 27.23s , +02d 32m 24.0s) |   C |   120 | 17.8 |        
     821 | 2022-08-10 23:25:37 |         MASTER-SAAO | (20h 36m 27.24s , +02d 32m 24.0s) |   C |   450 | 18.3 |  Coadd 
     821 | 2022-08-10 23:28:08 |         MASTER-SAAO | (20h 36m 30.98s , +02d 34m 05.9s) |   C |   150 | 17.9 |        
    1018 | 2022-08-10 23:31:09 |         MASTER-SAAO | (20h 36m 24.61s , +02d 33m 36.9s) |   C |   180 | 17.4 |        
    1228 | 2022-08-10 23:34:40 |         MASTER-SAAO | (20h 36m 24.10s , +02d 34m 44.8s) |   C |   180 | 17.9 |        
    1438 | 2022-08-10 23:38:10 |         MASTER-SAAO | (20h 36m 29.40s , +02d 33m 51.2s) |   C |   180 | 17.8 |        
    1649 | 2022-08-10 23:41:41 |         MASTER-SAAO | (20h 36m 23.40s , +02d 32m 58.0s) |   C |   180 | 17.0 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32460
SUBJECT: GRB 220810A: MeerLICHT detection of two afterglow candidates
DATE:    22/08/12 15:23:28 GMT
FROM:    Simon de Wet at UCT  <dwtsim002@myuct.ac.za>

S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO), D. Pieterse (Radboud), P.M.
Vreeswijk (Radboud), A.J. Levan (Radboud) and D.B. Malesani (Radboud and
DAWN/NBI) report on behalf of the MeerLICHT consortium:

Following the detection of GRB 220810A by Fermi/GBM (Fermi GBM team, GCN
32455), the 0.6 m wide-field MeerLICHT optical telescope began a series of
automatically-triggered 60 s q-band exposures of a number of fields
encompassing the GBM error box. Observations began approximately 14 minutes
post-trigger at 23:30:01 UT on 2022 August 10, and continued for an hour.

A total of 20 fields encompassing a cumulative probability of 58% were
observed once each. Within our difference-imaging products for this dataset
we identify two new transient candidates with the following coordinates,
brightness, and observing times:

+---------------------------+-------------------------+----------------+------------------+----------+
| RA (J2000)                | Dec (J2000)             | Mag (AB)       |
5-sigma limiting | UT time  |
|                           |                         |                |
 mag (AB)        |          |
+---------------------------+-------------------------+----------------+------------------+----------+
| 20:45:15.77 (311.31569d)  | +05:06:39.95 (5.11110d) | 11.51 +/- 0.06 | q
> 15.79        | 23:59:19 |
+---------------------------+-------------------------+----------------+------------------+----------+
| 20:49:24.58 (312.35241d)  | +01:56:09.64 (1.93601d) | 17.52 +/- 0.07 | q
> 18.77        | 23:44:42 |
+---------------------------+-------------------------+----------------+------------------+----------+

These positions are calibrated against Gaia DR2 with a positional
uncertainty of 0.1" in each coordinate. We note that the first, bright
candidate was identified in an image in which the sources are trailed.
However, human inspection confirms that the source is not an artefact.

The position of both transients is within the 50% probability region of the
GBM error box, and no objects consistent with these positions and observing
times were found in the Minor Planet Centre database. We also note that no
underlying source is visible in archival PanSTARRS images at these
positions.

We obtained further observations of the second, fainter source on the
following night and obtained a 5-sigma limiting magnitude of q > 19.22 at
the transient position, consistent with fading behaviour. Further follow-up
observations are encouraged in order to determine if either of these
sources is the afterglow of GRB 220810A.

MeerLICHT is built and run by a consortium consisting of Radboud
University, the University of Cape Town, the South African Astronomical
Observatory, the University of Oxford, the University of Manchester and the
University of Amsterdam.


GRB_name: GRB220810A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32461
SUBJECT: GRB 220810A: Swift ToO observations
DATE:    22/08/12 18:42:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the Fermi/GBM GRB 220810A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021510

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 Fermi/GBM 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: GRB220719A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32463
SUBJECT: GRB 220719A: Detection by VZLUSAT-2
DATE:    22/08/13 05:34:11 GMT
FROM:    Masanori Ohno at Hiroshima U  <ohno@astro.hiroshima-u.ac.jp>

J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), M. Ohno (Hiroshima U.),
 N. Werner  (Masaryk U.),  L. Meszaros (Konkoly Observatory), H. Takahashi
(Hiroshima U.), B. Csak (Konkoly Observatory), M. Topinka, F. Munz, F.
Hroch, M. Dafcikova, J.-P. Breuer, N. Husarikova (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.

A long-duration GRB 220719A (triggered by KONUS-Wind at 2022/07/19
19:09:46.939 UT; also detected by INTEGRAL/SPI-ACS with peak at 2022/07/19
19:09:45.0 UT - private communication with Dmitry Svinkin) was detected by
a 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 6.2
sigma detection was confirmed at the peak time 2022-07-19 19:09:43.5 UTC.
The GRB has the T90 duration of 7 s.

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB220719A_GCN_VZLUSAT2.pdf

GRB detectors on VZLUSAT-2 are a demonstration payload for a future
CubeSats 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.

We acknowledge the help of Dmitry Svinkin (Ioffe Institute) and Anastasia
Tsvetkova (Ioffe Institute) with the confirmation that this event was a
long GRB and also detected by INTEGRAL/SPI-ACS.


GRB_name: GRB220810A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32464
SUBJECT: GRB 220810A: Swift-XRT observations
DATE:    22/08/13 09:28:21 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P.
Beardmore (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri
(INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the second optical
afterglow candidate observed by MeerLICHT (de Wet et al. GCN Circ.
32460) of the Fermi/GBM detected burst GRB 220810A (Fermi GBM team, GCN

32455), collecting 4.9 ks of Photon Counting (PC) mode data between
T0+156.3 ks and T0+180.2 ks. 

No X-ray sources have been detected consistent with being within 9.9
arcsec of the MeerLICHT optical afterglow candidate position. The
3-sigma upper limit in the field is 0.003 ct  s^-1, corresponding to a
0.3-10 keV observed flux of 1.1e-13 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021510.

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


GRB_name: GRB220813A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32465
SUBJECT: GRB 220813A: Swift detection of a burst with an optical counterpart
DATE:    22/08/13 19:35:48 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. G. Bernardini (INAF-OAB), R. Brivio (INAF-OAB),
M. Ferro (INAF-OAB), J.D. Gropp (PSU), A. Melandri (INAF-OAB),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. M. Parsotan (GSFC/UMBC/CRESSTII), T. Sbarrato (INAF-OAB) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 19:23:03 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220813A (trigger=1120270).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 81.501, -32.985 which is 
   RA(J2000) = 05h 26m 00s
   Dec(J2000) = -32d 59' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peak
structure with a duration of about 30 sec.  The peak count rate
was ~1200 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 19:24:34.2 UT, 90.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 81.53235,
-33.01546 which is equivalent to:
   RA(J2000)  = 05h 26m 07.76s
   Dec(J2000) = -33d 00' 55.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 144 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. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.32 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.7
(+3.14/-2.65) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 100 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 05:26:07.57 =  81.53155
  DEC(J2000) = -33:00:58.9  = -33.01636
with a 90%-confidence error radius of about 0.67 arc sec. This position is 4.7
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.61 with a 1-sigma error of about  0.17. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.022. 

Burst Advocate for this burst is M. G. Bernardini (grazia.bernardini AT brera.inaf.it). 
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: GRB220813A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32466
SUBJECT: GRB 220813A: Enhanced Swift-XRT position
DATE:    22/08/14 02:15:47 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 4997 s of XRT Photon Counting mode data and 11 UVOT
images for GRB 220813A, 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 = 81.53144, -33.01688 which is equivalent
to:

RA (J2000): 05h 26m 7.55s
Dec (J2000): -33d 01' 00.8"

with an uncertainty of 2.0 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: GRB220813A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32467
SUBJECT: Swift GRB 220813A: Global MASTER-Net observations report 
DATE:    22/08/14 06:44:23 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

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


MASTER-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 220813A ( M. G. Bernardini et al., GCN 32465) errorbox  40368 sec after notice time and 40414 sec after trigger time at 2022-08-14 06:36:37 UT, with upper limit up to  17.0 mag. The observations began at zenith distance = 72 deg. The sun  altitude  is -58.5 deg. 

The galactic latitude b = -31 deg., longitude l = 237 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2055501

We obtain a following upper limits.  

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

   40504 |         MASTER-OAFA |   C |   180 | 17.0 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220813A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32468
SUBJECT: GRB 220813A: Swift-XRT refined Analysis
DATE:    22/08/14 06:47:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), P.A. Evans (U.
Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), T.
Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU) and
M.G. Bernardini report on behalf of the Swift-XRT team:

We have analysed 8.4 ks of XRT data for GRB 220813A (Bernardini et al.
GCN Circ. 32465), from 80 s to 30.0 ks after the  BAT trigger. The data
comprise 149 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Osborne et
al. (GCN Circ. 32466).

The late-time light curve (from T0+4.9 ks) can be modelled with a
power-law decay with a decay index of alpha=0.98 (+0.15, -0.14).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.53 (+/-0.13). The
best-fitting absorption column is  1.37 (+0.29, -0.27) x 10^21 cm^-2,
in excess of the Galactic value of 2.3 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.00 (+/-0.13) and a
best-fitting absorption column of 4.9 (+2.9, -2.6) x 10^20 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.2 x 10^-11 (3.6 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.9 (+2.9, -2.6) x 10^20 cm^-2
Galactic foreground: 2.3 x 10^20 cm^-2
Excess significance: 1.7 sigma
Photon index:      2.00 (+/-0.13)

If the light curve continues to decay with a power-law decay index of
0.98, the count rate at T+24 hours will be 9.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.1 x
10^-13 (3.5 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01120270.

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


GRB_name: GRB220810A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32469
SUBJECT: GRB 220810A: Further Swift-XRT observations
DATE:    22/08/14 08:30:56 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), 
J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) 
and P.A.  Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the first optical afterglow candidate observed by 
MeerLICHT (de Wet et al. GCN Circ. 32460) of the Fermi/GBM detected burst GRB 220810A 
(Fermi GBM team, GCN 32455), collecting 2.0 ks of Photon Counting (PC) mode data between 
T0+202.1 ks and T0+208.1 ks. 

No X-ray sources have been detected at the MeerLICHT optical afterglow candidate position. 
The 3-sigma upper limit in the field is 0.006 ct  s^-1, corresponding to a 0.3-10 keV observed flux 
of 2.2e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).


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


GRB_name: GRB220813A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32470
SUBJECT: GRB 220813A: Swift/UVOT Detection
DATE:    22/08/14 09:55:19 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and M. G. Bernardini (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220813A
100 s after the BAT trigger (Bernardini et al., GCN Circ. 32465).
A source consistent with the XRT position (Osborne et al.,
GCN Circ. 32466) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  05:26:07.60 =  81.53166 (deg.)
    Dec (J2000) = -33:00:59.0  = -33.01638 (deg.)
with an estimated uncertainty of 0.52 arc sec. (radius, 90% confidence).

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              100          250          147         19.67 +/- 0.11
v                  589         1581          117        >18.3
b                  515         1506           97        >19.6
u                  258         1652          360        >20.6
w1                 638         1630          117        >19.6
m2                 613         1605          117        >20.1
w2                 564         1556          117        >20.0

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: GRB220813A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32471
SUBJECT: GRB 220813A: VLT optical observations and possible host galaxy
DATE:    22/08/14 12:52:42 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

H. Fausey (GWU), Z.P. Zhu (NAOC, HUST), P. D'Avanzo (INAF-OAB), D. B. 
Malesani (Radboud Univ. and DAWN/NBI), L. Izzo (DARK/NBI), D. A. Kann 
(IAA-CSIC), D. Xu (NAOC) report on behalf of the Stargate collaboration:

We observed the field of GRB 220813A (Bernardini et al., GCN 32465) 
using the ESO VLT/UT3 equipped with the X-shooter acquisition camera. 
Observations started at 08:06:45 UT on 2022-08-14 (i.e., ~12.73 hr after 
the BAT trigger) and consisted of 3x60 s, 4x60 s, 3x60 s exposures in 
the Sloan g-/r-/z- bands, respectively.

The previously reported optical afterglow (Bernardini et al., GCN 32465; 
Kuin & Bernardini, GCN 32470) is marginally detected in the stacked 
r-band image with r ~  21.8 mag (AB), and is not detected in g-band and 
z-band with upper limits of g > 22.1 and z > 19.9, respectively (both AB).

In addition, we note that from Legacy Survey there exists a source at 
coordinates R.A. (J2000) = 05:26:07.5 and Dec.(J2000) = -33:00:59.2, 
being consistent with the Swift/UVOT position, which has photometric 
magnitudes of g ~ 24.99, r ~ 24.28 and z ~ 23.76 as well as photometric 
redshift of z ~ 0.82, which is the likely host galaxy of GRB 220813A.

We thank the great support of the ESO VLT staff, in particular Steffen 
Mieske and Michael Abdul-Masih.


GRB_name: GRB220813A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32472
SUBJECT: Konus-Wind detection of GRB 220813A
DATE:    22/08/15 12:02:50 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long GRB 220813A (Swift detection: Bernardini et al., GCN 32465)
was detected by Konus-Wind (KW) in the waiting mode.

A Bayesian block analysis of the KW waiting mode data in the 20-400 keV band
reveals a >6 sigma count rate increase in the interval
from T0-8.841 s to T0+5.879 s where T0 = T0(BAT) = 19:23:03.577 UT.

The KW light curve of this burst is available
at http://www.ioffe.ru/LEA/GRBs/GRB220813A/

Modeling a time-integrated spectrum of the burst (from T0-8.841 s to T0+8.823 s)
by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.81 (-0.12, + 0.12) and Ep = 242(-17,+23) keV.
In the 10 keV -10 MeV band, standard for the KW analysis,
the burst fluence is (1.41 Â± 0.14)x10^-6 erg/cm^2
and the 2.944 s peak energy flux is (1.30 Â± 0.13)x10^-7 erg/cm^2/s.

Assuming the likely host galaxy redshift z=0.82 (Fausey et al., GCN 32471)
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 ~2.7x10^51 erg,
the isotropic peak luminosity L_iso to ~8.0x10^50 erg/s,
and the rest-frame peak energy of the spectrum Ep,z to ~440 keV.
With the obtained estimates, GRB 220813A is a hard-spectrum / low-luminosity outlier
in both 'Amati' and 'Yonetoku' relations 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/GRB220813A/GRB220813A_rest_frame.pdf

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


GRB_name: GRB220821A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32473
SUBJECT: GRB 220821A: Fermi GBM Final Real-time Localization
DATE:    22/08/21 07:16:03 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 07:05:35 UT on 21 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220821A (trigger 682758340.440514 / 220821296).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 133.6, Dec = 28.7 (J2000 degrees, equivalent to J2000 08h 54m, 28d 41'), with a statistical uncertainty of 3.6 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/2022/bn220821296/quicklook/glg_skymap_all_bn220821296.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220821296/quicklook/glg_healpix_all_bn220821296.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220821296/quicklook/glg_lc_medres34_bn220821296.gif


GRB_name: GRB220823A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32476
SUBJECT: GRB 220823A: Swift/BAT-GUANO detection of a short burst
DATE:    22/08/23 15:23:02 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

Aaron Tohuvavohu (U Toronto), James DeLaunay (UAlabama), Gayathri Raman
(PSU), Jamie A. Kennea (PSU), report:

Swift/BAT did not localize GRB 220823A onboard (T0: 2022-08-23T03:28:52
 UTC, Fermi/GBM trig #682918137).

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, GUANO sent a command to the Swift Burst Alert Telescope (BAT)
to save 200 seconds of BAT event-mode data from [-45,+45] 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,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 13.4 in a 1.024 s
analysis time bin.

The duration of the burst as seen by BAT is T90~1.4 s.

NITRATES results, independently, are ambiguous with respect to whether this
burst originates from in or outside the BAT FOV, with a borderline
DeltaLLHOut of 9.9 and no specific location in the FOV significantly
preferred.
Effort to localize this burst will continue.

Independent spectral and/or fluence measurements of this burst from other
instruments could help determine the preferred spatial origin.

See Section 9.1 and Figure 20 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://www.swift.psu.edu/guano/


GRB_name: GRB220823A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32479
SUBJECT: GRB 220823A: Fermi GBM detection
DATE:    22/08/24 16:43:38 GMT
FROM:    Boyan A. Hristov at UAH  <bah0046@uah.edu>

B. Hirstov (UAH) and C. Fletcher (USRA)
report on behalf of the Fermi GBM Team:

"At 03:28:52.39 UT on 23 August 2022, the Fermi Gamma-Ray
Burst Monitor (GBM) triggered and located GRB 220823A
(trigger 682918137 / 220823145),which was also detected by
Swift/BAT-GUANO (A. Tohuvavohu et al. 2022, GCN 32476).

The on-ground calculated location, using the GBM trigger
data, is RA = 82.94, DEC = +2.44 (J2000 degrees, equivalent
to 05h, 31m, 2d 26'), with a statistical uncertainty of 3
degrees (radius, 1-sigma containment, statistical only;
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 at the GBM trigger
time is 15 degrees.

The GBM light curve consists of single peak with a duration
(T90) of 1.1 +/- 0.7 s (50-300 keV).

The time-averaged spectrum from T0-1.024 s to T0+0.256 s is
best fit by a power law with an exponential cutoff with
Epeak = 1189 +/- 608 keV and alpha = -0.52 +/- 0.26.

The event fluence (10-1000 keV) in this time interval is
(1.1 +/- 0.1)E-6 erg/cm^2. The 0.064-sec peak photon flux
measured starting from T0-0.064 s in the 10-1000 keV band
is 5 +/- 1 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: GRB220825A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32482
SUBJECT: GRB 220825A: Fermi GBM Final Localization
DATE:    22/08/25 16:46:46 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

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

At 01:57:48.50 UT on 25 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220825A (trigger 683085473 / 220825082).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 87.9, Dec = -10.8 (J2000 degrees, equivalent to J2000 05h 52m, -10d 48'), with a statistical uncertainty of 5.7 degrees.

The angle from the Fermi LAT boresight is 115.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220825082/quicklook/glg_skymap_all_bn220825082.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220825082/quicklook/glg_healpix_all_bn220825082.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220825082/quicklook/glg_lc_medres34_bn220825082.gif


GRB_name: GRB220825A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32483
SUBJECT: GRB 220825A: Swift/BAT-GUANO detection
DATE:    22/08/26 04:07:21 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), report:

Swift/BAT did not localize GRB 220825A onboard (T0: 2022-08-25T01:57:48
 UTC, Fermi/GBM trig #683085473).

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, GUANO sent a command to the Swift Burst Alert Telescope
(BAT) to save 200 seconds of BAT event-mode data from [-45,+45]
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,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 9.1 in a
16.384 s analysis time bin.

NITRATES results, independently, are ambiguous with respect to whether
this burst originates from in or outside the BAT FOV, with a
borderline DeltaLLHOut of 7.7 and no specific location in the FOV
significantly preferred.

Independent spectral and/or fluence measurements of this burst from
other instruments could help determine the preferred spatial origin.

See Section 9.1 and Figure 20 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://www.swift.psu.edu/guano/


GRB_name: GRB220826A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32484
SUBJECT: GRB 220826A: Swift detection of a burst with an optical counterpart
DATE:    22/08/26 12:05:48 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

R. Caputo (GSFC), P. A. Evans (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 11:55:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220826A (trigger=1121751).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 206.431, -44.044 which is 
   RA(J2000) = 13h 45m 44s
   Dec(J2000) = -44d 02' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 20 sec.  The peak count rate
was ~3500 counts/sec (15-350 keV), at ~7 sec after the trigger. 

The XRT began observing the field at 11:56:42.9 UT, 81.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 206.41169, -44.03885 which
is equivalent to:
   RA(J2000)  = 13h 45m 38.81s
   Dec(J2000) = -44d 02' 19.9"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 53 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. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (9.05 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.8
(+2.60/-2.30) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 90 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 13:45:38.52 = 206.41049
  DEC(J2000) = -44:02:19.0  = -44.03862
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.89 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.110. 

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: GRB220826A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32485
SUBJECT: GRB 220826A: Enhanced Swift-XRT position
DATE:    22/08/26 14:54:34 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 744 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 220826A, 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 = 206.41081, -44.03917 which is equivalent
to:

RA (J2000): 13h 45m 38.59s
Dec (J2000): -44d 02' 21.0"

with an uncertainty of 2.2 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: GRB220826A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32486
SUBJECT: Swift GRB 220826A: Global MASTER-Net observations report 
DATE:    22/08/26 17:24:17 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220826A ( R. Caputo et al., GCN 32484) errorbox  19090 sec after notice time and 19104 sec after trigger time at 2022-08-26 17:13:46 UT, with upper limit up to  17.8 mag. Observations started at twilight.  The observations began at zenith distance = 39 deg. The sun  altitude  is -12.5 deg. 

The galactic latitude b = 17 deg., longitude l = 314 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2068190

We obtain a following upper limits.  

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

   19194 |         MASTER-SAAO |   C |   180 | 17.8 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220826A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32487
SUBJECT: GRB 220826A: iTelescope optical afterglow observations
DATE:    22/08/26 17:55:46 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997@gmail.com>

I observed the field of GRB 220826A (Caputo et al., GCN Circ. 32484)
using remote telescope T59 (0.51-m f/6.8 reflector + CCD) of
iTelescope.Net in Siding Spring Observatory (Australia) on 2022-08-26.
Three images were obtained from 12:16:07 UTC (1246 sec. after the
trigger) with a Luminance filter (300 seconds exposures, BINx1), but
in the third of them, the object is already below the minimum target
elevation for the telescope.

I clearly detected (SNR ~ 8 in the stacked image) the optical
afterglow with UVOT position and measured its magnitude = 19.3 +/- 0.2
in the stacked image (midtime = 12:23:09 UTC means 1668 sec. after the
trigger), airmass was from 4.041 to 4.463. I compared with Sloan r'
magnitudes of nearby stars from APASS DR9 catalogue (Henden et al.,
2016).

Magnitude was not corrected for Galactic extinction.

Stacked image available here:
https://www.flickr.com/photos/filipp-romanov/52313060415


GRB_name: GRB220826A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32488
SUBJECT: GRB 220826A: Swift/UVOT Detection
DATE:    22/08/26 18:47:37 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and R. Caputo (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220826A
91 s after the BAT trigger (Caputo et al., GCN Circ. 32484).
A source consistent with the XRT position (Beardmore et al. GCN Circ. 32485)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  13:45:38.51 = 206.41047 (deg.)
    Dec (J2000) = -44:02:19.2  = -44.03866 (deg.)
with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence).

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               91          240          147         18.12 +/- 0.05
v                  632          827           39        >18.4
b                  559          753           39        >18.6
u                  303          553          246         18.69 +/- 0.13
w1                 682          702           19        >17.7
m2                 831          851           19        >17.8
w2                 608          802           39        >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.110 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB220826A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32489
SUBJECT: GRB 220826A: Lesedi optical afterglow detection
DATE:    22/08/26 18:59:01 GMT
FROM:    Simon de Wet at UCT  <dwtsim002@myuct.ac.za>

S. de Wet (UCT) and D.B. Malesani (Radboud and DAWN/NBI) report:

Following the detection of GRB 220826A by Swift and its X-ray and optical
counterparts (Caputo et al., GCN 32484; Kuin et al., GCN 32488; Romanov
F.P., GCN 32487), the 1m Lesedi optical telescope located at Sutherland,
South Africa, obtained 600 s exposures in each of the g,r,i and z bands
with the Mookodi low-resolution spectrograph and imager beginning at
17:27:09 UT, approximately 0.23 days post-trigger.

We detect the optical afterglow to GRB 220826A in each image at the UVOT
position with the following AB magnitude, calibrated to Skymapper flux
measurements of a nearby star in the field:

r = 21.48 +/- 0.16

Lesedi is built and operated by the South African Astronomical Observatory.


GRB_name: GRB220825A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32490
SUBJECT: GRB 220825A: Fermi GBM observation
DATE:    22/08/26 20:30:29 GMT
FROM:    Sarah Dalessi at UAH  <sd0104@uah.edu>

S. Dalessi (UAH), C. Fletcher (USRA), C. Meegan (UAH), and J. Wood (NASA MFSC)
report on behalf of the Fermi GBM Team:

"At 01:57:48.50 UT on 25 August 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220825A (trigger 683085473 / 220825082),
which was also detected by the Swift/BAT-GUANO (J. DeLaunay et al.
2022, GCN 32483).

The angle from the Fermi LAT boresight at the GBM trigger time is 115.0 degrees.

The GBM light curve consists of a single peak burst
with a duration (T90) of about 14.1 s (50-300 keV).
The time-averaged spectrum from T0-4.1 s to T0+8.2 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.24 +/- 0.19 and
the cutoff energy, parameterized as Epeak, is 56.6 +/- 7.0 keV

The event fluence (10-1000 keV) in this time interval is
(1.83 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.98 s in the 10-1000 keV band
is 4.96 +/- 0.37 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 46.2 +/- 9.5 keV, alpha = -0.96 +/- 0.37 and beta = -2.48 +/- 0.32.

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: GRB220826A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32491
SUBJECT: GRB 220826A: Swift-XRT refined Analysis
DATE:    22/08/27 00:49:19 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), M.G.
Bernardini (INAF-OAB), E. Ambrosi  (INAF-IASFPA) , D.N. Burrows (PSU),
J. D. Gropp (PSU) and R. Caputo report on behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 220826A (Caputo et al. GCN
Circ. 32484), from 70 s to 33.8 ks after the  BAT trigger. The data
comprise 37 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 32485).

The late-time light curve (from T0+5.0 ks) can be modelled with a
power-law decay with a decay index of alpha=1.25 (+/-0.18).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.80 (+0.16, -0.15). The
best-fitting absorption column is  1.6 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 9.1 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 3.9 x 10^-11 (4.8 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.6 (+/-0.5) x 10^21 cm^-2
Galactic foreground: 9.1 x 10^20 cm^-2
Excess significance: 2.4 sigma
Photon index:      1.80 (+0.16, -0.15)

If the light curve continues to decay with a power-law decay index of
1.25, the count rate at T+24 hours will be 5.0 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x
10^-13 (2.4 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01121751.

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


GRB_name: GRB220826A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32495
SUBJECT: GRB 220826A: Fermi GBM observation
DATE:    22/08/27 11:13:39 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

P. Veres and C. Meegan (both UAH)
report on behalf of the Fermi GBM Team:

"At 11:55:22.98 UT on 26 August 2022, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 220826A (trigger 220826497 / 683207727)
which was also detected by the Swift/BAT (Caputo et al., GCN 32484)
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 54
degrees.

The GBM light curve shows  two pulses
with a duration (T90) of about 16.6 s (50-300 keV).
The time-averaged spectrum from T0-0.5 s to T0+10.8 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.66 +/- 0.20 and
the cutoff energy, parameterized as Epeak, is 113 +/- 14 keV

The event fluence (10-1000 keV) in this time interval is
(1.50 +/- 0.14)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 + 5.2 s in the 10-1000 keV band
is 4.3 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 66 +/- 13 keV, alpha = 0.28 +/- 0.58 and beta = -2.14 +/- 0.18.

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: GRB220826A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32496
SUBJECT: GRB 220826A: Swift-BAT refined analysis
DATE:    22/08/27 19:50:26 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), 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/UMBC),
R. Caputo (GSFC), M. Stamatikos (OSU)
(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 220826A (trigger #1121751)
(Caputo et al., GCN Circ. 32484).  The BAT ground-calculated position is
RA, Dec = 206.421, -44.036 deg which is
   RA(J2000)  =  13h 45m 41.0s
   Dec(J2000) = -44d 02' 10.1"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 92%.

The mask-weighted light curve shows a multi-peaked structure that
starts at ~T0 and ends at ~T+13 s. There are roughly three main
peaks at ~T+1 s, ~T+7 s, and ~T+11 s. respectively.
T90 (15-350 keV) is 11.14 +- 1.02 sec (estimated error including
systematics).

The time-averaged spectrum from T-0.20 to T+13.01 sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 1.44 +- 0.10.  The fluence in the 15-150 keV band
is 1.2 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured
from T+6.58 sec in the 15-150 keV band is 2.6 +- 0.2 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1121751/BA/


GRB_name: GRB220827A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32497
SUBJECT: GRB 220827A: Fermi GBM Final Real-time Localization
DATE:    22/08/27 21:40:19 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 21:30:03 UT on 27 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220827A (trigger 683328608.07386 / 220827896).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 113.1, Dec = -1.1 (J2000 degrees, equivalent to J2000 07h 32m, -1d 06'), with a statistical uncertainty of 15.1 degrees.

The angle from the Fermi LAT boresight is 99.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220827896/quicklook/glg_skymap_all_bn220827896.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220827896/quicklook/glg_healpix_all_bn220827896.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220827896/quicklook/glg_lc_medres34_bn220827896.gif


GRB_name: GRB220826A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32500
SUBJECT: Konus-Wind detection of GRB 220826A
DATE:    22/08/29 17:46:51 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long GRB 220826A (Swift detection: Caputo et al., GCN 32484;
Fermi GBM observation: Veres & Meegan, GCN 32495)
was detected by Konus-Wind (KW) in the waiting mode.

A Bayesian block analysis of the KW waiting mode data in the 20-400 keV band
reveals a >10 sigma count rate increase in the interval
from T0-0.525 s to T0+37.747 s where T0 = T0(BAT) = 11:55:21.742 UT.

The KW light curve of this burst is available
at http://www.ioffe.ru/LEA/GRBs/GRB220826A/

Modeling a time-integrated spectrum of the burst
by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.48 (-0.22, + 0.25) and Ep = 113(-4,+4) keV.
In the 10 keV -10 MeV band, standard for the KW analysis,
the burst fluence is (2.53 Â± 0.29)x10^-6 erg/cm^2
and the 2.944 s peak energy flux is (2.86 Â± 0.18)x10^-7 erg/cm^2/s.

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


GRB_name: GRB220831A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32506
SUBJECT: GRB 220831A: Swift/BAT-GUANO localization of a short burst
DATE:    22/09/01 01:55:51 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), James DeLaunay
(UAlabama), Gayathri Raman (PSU),  report:

Swift/BAT did not successfully trigger on GRB 220831A (T0: 2022-08-31
13:56:33 UTC).

10 seconds of serendipitous event data is available covering the time
of this burst, associated with BAT failed trigger #1122435. This data
was produced due to an unrelated event that occurred close in time to
this burst. There is no long duration GUANO data available for this
burst due to lack of prompt notice from other instruments.

The duration of the burst, as seen by BAT, is ~1 second.

In ground analysis of the available event data, we find the position of
the burst with SNR 15.0 in the image domain.

The BAT position is
RA, Dec = 24.2550 -41.5818, which is:
    RA (J2000)     01h 37m 01.2s
    Dec (J2000)  -41d 34' 54.5"
with an estimated uncertainty of 2 arcminutes.

XRT and UVOT follow-up has been requested. Results of follow-up
observations will be reported in future circulars.


GRB_name: GRB220831A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32508
SUBJECT: GRB 220831A: Swift ToO observations
DATE:    22/09/01 04:19:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 220831A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021512

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: GRB220831B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32509
SUBJECT: GRB 220831B: Fermi GBM Final Localization
DATE:    22/09/01 16:45:13 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

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

At 13:11:36.16 UT on 31 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220831B (trigger 683644301 / 220831550).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 167.3, Dec = +1.0 (J2000 degrees, equivalent to J2000 11h 09m, +01d 00'), with a statistical uncertainty of 4.7 degrees.

The angle from the Fermi LAT boresight is 63.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220831550/quicklook/glg_skymap_all_bn220831550.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220831550/quicklook/glg_healpix_all_bn220831550.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220831550/quicklook/glg_lc_medres34_bn220831550.gif


GRB_name: GRB220831A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32510
SUBJECT: GRB 220831A: Swift-XRT observations
DATE:    22/09/01 16:49:42 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. Dichiara (PSU), A.P. Beardmore (U. Leicester), E. Ambrosi 
(INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR),
J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P.
Osborne (U. Leicester) and P.A. Evans (U. Leicester) report on behalf
of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 220831A (Tohuvavohu et al. GCN Circ.
32506), collecting 5.0 ks of Photon Counting (PC) mode data between
T0+51.2 ks and T0+78.8 ks. 

No X-ray sources have been detected consistent with being within 98
arcsec of the Swift/BAT position. The 3-sigma upper limit in the field
ranges from ~0.002 to ~0.003 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 8.1e-14 to 1.1e-13 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

We report, however, the presence of a low-significance source, at the
following position:
RA (J2000):  24.25359  = 01:37:00.86
Dec (J2000): -41.59325 = -41:35:35.70
Error: 6.8 arcsec (radius, 90% conf.)
Distance: 41 arcsec from Swift-BAT position.

Given the low-significance detection, we cannot state at the present
stage if this detection is real or spurious.

Six uncatalogued sources were detected too far from the GRB position to
be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021512.

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


GRB_name: GRB220831A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32511
SUBJECT: GRB 220831A: Fermi GBM observation
DATE:    22/09/01 17:55:47 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

J. Wood (NASA/MSFC) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 13:56:32.93 UT on 31 Aug 2022, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 220831A (trigger 683646997 / 220831581).
which was also detected by the Swift/BAT-GUANO (A. Tohuvavohu et al. 2022, GCN 32506)
The GBM on-ground location is consistent with the Swift position.

The on-ground calculated location, using the GBM trigger
data, is RA = 28.1, DEC = -45.1 (J2000 degrees,
equivalent to 01h 52m, -45d 06'), with an uncertainty
of 7.9 degrees (radius, 1-sigma containment,
statistical only; 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 102.0 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 1.7 s (50-300 keV).
The time-averaged spectrum from T0-0.5 s to T0+1.3 s is
best fit by a Band function with Epeak = 46 +/- 8 keV,
alpha = -0.67 +/- 0.45, and beta = -2.7 +/- 0.4

The event fluence (10-1000 keV) in this time interval is
(5.0 +/- 0.5)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.2 s in the 10-1000 keV band
is 9.4 +/- 1.7 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: GRB220831C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32512
SUBJECT: GRB 220831C: Fermi GBM Final Localization
DATE:    22/09/01 17:57:06 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

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

At 15:56:35.37 UT on 31 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220831C (trigger 683654200 / 220831664).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 337.0, Dec = -47.6 (J2000 degrees, equivalent to J2000 22h 28m, -47d 36'), with a statistical uncertainty of 8.6 degrees.

The angle from the Fermi LAT boresight is 69.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220831664/quicklook/glg_skymap_all_bn220831664.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220831664/quicklook/glg_healpix_all_bn220831664.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220831664/quicklook/glg_lc_medres34_bn220831664.gif


GRB_name: GRB220831A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32513
SUBJECT: GRB 220831A, VLT/HAWK-I near-infrared observations
DATE:    22/09/01 20:48:48 GMT
FROM:    Daniele B Malesani at Radboud U  <d.malesani@astro.ru.nl>

P. D'Avanzo (INAF/OABr), A. Rossi (INAF/OAS), D. B. Malesani (Radboud 
and DAWN/NBI), S. Campana (INAF/OABr), A. J. Levan (Radboud univ.) 
report on behalf of the Stargate collaboration:

Following the report of the Swift/BAT/GUANO GRB 220831A (Tohuvavohu et 
al., GCN 32506; see also Wood & Meegan, GCN 32511) we observed the BAT 
error circle with the ESO Very Large Telescope, equipped with the HAWK-I 
near-infrared camera. Observations consisted in 20 min exposure in the J 
band, with a mean time of 19.4 hr after the GRB.

Lacking a deep reference image to check for variability, no claim of a 
new object can be made based solely on our data. Within the BAT error 
circle, several objects are apparent in the HAWK-I image which are not 
visible in the the Legacy survey (z and r bands), which are likely due 
to color effects.

A source is visible in the HAWK-I image which is consistent with the 
weak X-ray source reported by Dichiara et al. (GCN 32510), at 
coordinates (J2000):

RA = 01:37:00.95
Dec = -41:35:34.37

Its Vega magnitude is J = 21.9 +- 0.09, calibrated against one 2MASS 
star, and is not detected in the Legacy survey down to limiting 
magnitudes z > 23.1, r > 24 (all AB).


We also note the presence of the nearby galaxy NGC 625, with a NED 
distance ~4 Mpc, which is 23.6 arcmin (~30 kpc in projection) away from 
the BAT coordinates of GRB 220831A.

We acknowledge the support of the observing staff at Paranal. Further 
observations are planned.


GRB_name: GRB220902A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32514
SUBJECT: GRB 220902A: Fermi GBM Final Real-time Localization
DATE:    22/09/02 10:41:15 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 10:30:00 UT on 2 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220902A (trigger 683807405.374026 / 220902438).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 30.5, Dec = 40.9 (J2000 degrees, equivalent to J2000 02h 01m, 40d 53'), with a statistical uncertainty of 8.6 degrees.

The angle from the Fermi LAT boresight is 44.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220902438/quicklook/glg_skymap_all_bn220902438.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220902438/quicklook/glg_healpix_all_bn220902438.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220902438/quicklook/glg_lc_medres34_bn220902438.gif


GRB_name: GRB220902A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32515
SUBJECT: Fermi GRB 220902A: Global MASTER-Net observations report 
DATE:    22/09/02 12:30:13 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220902A ( Fermi GBM team, GCN 32514) errorbox  2349 sec after notice time and 2355 sec after trigger time at 2022-09-02 11:09:15 UT, with upper limit up to  17.5 mag. Observations started at twilight.  The observations began at zenith distance = 68 deg. The sun  altitude  is -9.2 deg. 

The galactic latitude b = -20 deg., longitude l = 138 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2076127

We obtain a following upper limits.  

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

    2445 | 2022-09-02 11:09:15 |         MASTER-Amur | (01h 44m 16.57s , +43d 33m 10.9s) |   C |   180 | 15.2 |        
    2586 | 2022-09-02 11:12:36 |         MASTER-Amur | (01h 41m 55.38s , +42d 56m 13.2s) |   C |    60 | 15.2 |        
    2665 | 2022-09-02 11:13:55 |         MASTER-Amur | (01h 52m 57.09s , +42d 56m 40.7s) |   C |    60 | 15.3 |        
    2745 | 2022-09-02 11:15:15 |         MASTER-Amur | (02h 06m 31.37s , +44d 51m 20.2s) |   C |    60 | 15.1 |        
    2825 | 2022-09-02 11:16:35 |         MASTER-Amur | (02h 17m 51.30s , +44d 52m 57.7s) |   C |    60 | 15.1 |        
    2905 | 2022-09-02 11:17:54 |         MASTER-Amur | (02h 02m 41.77s , +42d 58m 40.8s) |   C |    60 | 15.4 |        
    2984 | 2022-09-02 11:19:14 |         MASTER-Amur | (02h 13m 43.67s , +42d 57m 58.7s) |   C |    60 | 15.3 |        
    3064 | 2022-09-02 11:20:34 |         MASTER-Amur | (01h 39m 11.33s , +41d 02m 27.1s) |   C |    60 | 15.6 |        
    3144 | 2022-09-02 11:21:54 |         MASTER-Amur | (01h 49m 45.27s , +41d 03m 49.1s) |   C |    60 | 15.7 |        
    3225 | 2022-09-02 11:23:15 |         MASTER-Amur | (01h 36m 36.70s , +39d 09m 25.8s) |   C |    60 | 15.8 |        
    3365 | 2022-09-02 11:24:35 |         MASTER-Amur | (01h 40m 08.32s , +43d 30m 33.6s) |   C |   180 | 16.7 |        
    3505 | 2022-09-02 11:27:55 |         MASTER-Amur | (01h 46m 49.98s , +39d 09m 40.3s) |   C |    60 | 16.1 |        
    3584 | 2022-09-02 11:29:14 |         MASTER-Amur | (01h 42m 00.61s , +42d 56m 27.1s) |   C |    60 | 16.4 |        
    3664 | 2022-09-02 11:30:34 |         MASTER-Amur | (01h 52m 50.69s , +42d 55m 44.8s) |   C |    60 | 16.3 |        
    3744 | 2022-09-02 11:31:54 |         MASTER-Amur | (02h 06m 33.07s , +44d 50m 11.1s) |   C |    60 | 16.2 |        
    3824 | 2022-09-02 11:33:14 |         MASTER-Amur | (02h 17m 47.58s , +44d 51m 57.4s) |   C |    60 | 16.1 |        
    3904 | 2022-09-02 11:34:33 |         MASTER-Amur | (02h 02m 43.57s , +42d 56m 22.7s) |   C |    60 | 16.3 |        
    3983 | 2022-09-02 11:35:53 |         MASTER-Amur | (02h 13m 43.23s , +42d 57m 44.0s) |   C |    60 | 16.3 |        
    4063 | 2022-09-02 11:37:13 |         MASTER-Amur | (01h 39m 05.60s , +41d 02m 13.1s) |   C |    60 | 16.6 |        
    4143 | 2022-09-02 11:38:33 |         MASTER-Amur | (01h 49m 42.47s , +41d 03m 30.2s) |   C |    60 | 16.6 |        
    4222 | 2022-09-02 11:39:52 |         MASTER-Amur | (01h 36m 37.15s , +39d 08m 08.4s) |   C |    60 | 16.6 |        
    4302 | 2022-09-02 11:41:12 |         MASTER-Amur | (01h 59m 21.61s , +41d 01m 58.4s) |   C |    60 | 16.4 |        
    4442 | 2022-09-02 11:42:31 |         MASTER-Amur | (01h 40m 12.56s , +43d 31m 12.3s) |   C |   180 | 17.5 |        
    4581 | 2022-09-02 11:45:51 |         MASTER-Amur | (02h 09m 54.56s , +41d 02m 19.1s) |   C |    60 | 16.5 |        
    4661 | 2022-09-02 11:47:11 |         MASTER-Amur | (01h 46m 56.97s , +39d 08m 53.8s) |   C |    60 | 16.9 |        
    4741 | 2022-09-02 11:48:31 |         MASTER-Amur | (01h 41m 53.91s , +42d 56m 07.5s) |   C |    60 | 17.0 |        
    4821 | 2022-09-02 11:49:51 |         MASTER-Amur | (01h 52m 49.68s , +42d 57m 25.8s) |   C |    60 | 17.0 |        
    4901 | 2022-09-02 11:51:11 |         MASTER-Amur | (02h 06m 33.42s , +44d 50m 46.8s) |   C |    60 | 16.8 |        
    4981 | 2022-09-02 11:52:31 |         MASTER-Amur | (02h 17m 46.42s , +44d 50m 04.4s) |   C |    60 | 16.8 |        
    5060 | 2022-09-02 11:53:50 |         MASTER-Amur | (02h 02m 47.69s , +42d 56m 05.2s) |   C |    60 | 16.9 |        
    5140 | 2022-09-02 11:55:10 |         MASTER-Amur | (02h 13m 40.61s , +42d 57m 50.2s) |   C |    60 | 16.8 |        
    5220 | 2022-09-02 11:56:30 |         MASTER-Amur | (01h 39m 07.95s , +41d 01m 13.1s) |   C |    60 | 17.2 |        
    5324 | 2022-09-02 11:58:14 |         MASTER-Amur | (01h 49m 48.77s , +41d 02m 55.0s) |   C |    60 | 17.1 |        
    5407 | 2022-09-02 11:59:37 |         MASTER-Amur | (01h 36m 32.49s , +39d 07m 50.2s) |   C |    60 | 17.1 |        
    5487 | 2022-09-02 12:00:57 |         MASTER-Amur | (01h 59m 15.72s , +41d 03m 24.2s) |   C |    60 | 16.8 |        
    5570 | 2022-09-02 12:02:20 |         MASTER-Amur | (02h 09m 58.65s , +41d 02m 40.3s) |   C |    60 | 16.8 |        
    5650 | 2022-09-02 12:03:40 |         MASTER-Amur | (01h 46m 50.38s , +39d 07m 02.7s) |   C |    60 | 17.1 |        
    5730 | 2022-09-02 12:04:59 |         MASTER-Amur | (01h 56m 11.23s , +39d 09m 06.2s) |   C |    60 | 17.0 |        
    5809 | 2022-09-02 12:06:19 |         MASTER-Amur | (02h 06m 30.18s , +39d 07m 43.9s) |   C |    60 | 16.9 |        
    5890 | 2022-09-02 12:07:40 |         MASTER-Amur | (02h 19m 25.62s , +41d 02m 50.5s) |   C |    60 | 16.7 |        
    5969 | 2022-09-02 12:08:59 |         MASTER-Amur | (02h 30m 01.63s , +41d 04m 07.8s) |   C |    60 | 16.6 |        
    6049 | 2022-09-02 12:10:19 |         MASTER-Amur | (02h 15m 45.45s , +39d 07m 43.5s) |   C |    60 | 16.7 |        
    6129 | 2022-09-02 12:11:39 |         MASTER-Amur | (02h 26m 10.46s , +39d 08m 03.5s) |   C |    60 | 16.6 |        
    6209 | 2022-09-02 12:12:59 |         MASTER-Amur | (01h 53m 21.86s , +37d 13m 23.8s) |   C |    60 | 17.1 |        
    6289 | 2022-09-02 12:14:19 |         MASTER-Amur | (02h 03m 28.74s , +37d 15m 05.9s) |   C |    60 | 17.1 |        
    6369 | 2022-09-02 12:15:39 |         MASTER-Amur | (02h 12m 25.65s , +37d 15m 32.9s) |   C |    60 | 17.0 |        
    6448 | 2022-09-02 12:16:58 |         MASTER-Amur | (02h 22m 33.66s , +37d 14m 49.5s) |   C |    60 | 16.8 |        
    6528 | 2022-09-02 12:18:18 |         MASTER-Amur | (01h 59m 16.49s , +41d 01m 06.2s) |   C |    60 | 17.1 |        
    6608 | 2022-09-02 12:19:38 |         MASTER-Amur | (02h 09m 58.36s , +41d 01m 51.7s) |   C |    60 | 17.0 |        
    6690 | 2022-09-02 12:21:00 |         MASTER-Amur | (01h 56m 11.94s , +39d 08m 57.2s) |   C |    60 | 17.1 |        
    6770 | 2022-09-02 12:22:19 |         MASTER-Amur | (02h 06m 30.87s , +39d 07m 44.1s) |   C |    60 | 17.0 |        
    6857 | 2022-09-02 12:23:47 |         MASTER-Amur | (02h 19m 31.28s , +41d 03m 31.1s) |   C |    60 | 16.9 |        
    6937 | 2022-09-02 12:25:07 |         MASTER-Amur | (02h 30m 03.21s , +41d 02m 49.4s) |   C |    60 | 16.6 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32516
SUBJECT: GRB 220831A: DECam detection of a possible optical counterpart 
DATE:    22/09/02 15:47:51 GMT
FROM:    Anais Moller at Australian National U  <anais.moller@anu.edu.au>

GRB 220831A: DECam detection of a possible optical counterpart



J. Freeburn, N. Van Bemmel, D. Dobie, A. Moller, J. Cooke (Swinburne/OzGrav), M. Suhr (Swinburne/ASTRO 3D) report on behalf of the Deeper Wider Faster Collaboration



We have observed the Swift/BAT-GUANO localisation of GRB 220831A (GCN 32506) with the Dark Energy Camera (DECam) on the V. M. Blanco 4-m telescope. Imaging in g, r, i were carried out on UT dates 2022-08-31 and 2022-09-01 as part of an ongoing Deeper, Wider, Faster (DWF) program observing run.



We detect a source that is spatially coincident with the X-ray (GCN 32510) and near-infrared (GCN 32513) candidate counterpart and is not detected in archival imaging of the field.



RA = 01:37:0.965

DEC = -41:35:34.60



We measure:

59823.3  i = 23.13 +/-0.15

59824.3  i = 24.12 +/-0.28

59823.3  r = 23.06 +/-0.12

59824.3  r = 24.32 +/-0.20

59823.1  g < 23.9

59824.3  g < 24.6



Deep spectroscopy is encouraged. We will continue to monitor this source with DECam as part of DWF.


GRB_name: GRB220905A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32518
SUBJECT: GRB 220905A: Fermi GBM Final Real-time Localization
DATE:    22/09/05 11:39:12 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 11:28:43 UT on 5 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220905A (trigger 684070128.696976 / 220905478).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 343.5, Dec = -33.5 (J2000 degrees, equivalent to J2000 22h 53m, -33d 30'), with a statistical uncertainty of 1.0 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/2022/bn220905478/quicklook/glg_skymap_all_bn220905478.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220905478/quicklook/glg_healpix_all_bn220905478.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220905478/quicklook/glg_lc_medres34_bn220905478.gif


GRB_name: GRB220905A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32519
SUBJECT: GRB 220905A: BALROG localization (Fermi Trigger 684070128 / GRB 220905478)
DATE:    22/09/05 12:16:19 GMT
FROM:    Jochen Greiner at MPE,Garching  <jcg@mpe.mpg.de>

B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
684070128 at 11:28:43 on 05 Sept. 2022 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 (1 sigma statistical errors) is:
RA(2000.0) = 345.2+/-1.7 deg
Decl.(2000.0) = -35.4+/-1.5 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB220905478/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB220905478/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB220905478/json

                        


GRB_name: GRB220905A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32520
SUBJECT: Fermi GRB 220905A: Global MASTER-Net observations report 
DATE:    22/09/05 18:45:27 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220905A ( Fermi GBM team, GCN 32518) errorbox  20955 sec after notice time and 20989 sec after trigger time at 2022-09-05 17:18:33 UT, with upper limit up to  18.8 mag. Observations started at twilight.  The observations began at zenith distance = 64 deg. The sun  altitude  is -12.3 deg. 

The galactic latitude b = -65 deg., longitude l = 12 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2079144

We obtain a following upper limits.  

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

   21020 | 2022-09-05 17:18:33 |         MASTER-SAAO | (22h 51m 26.96s , -33d 15m 04.5s) |   C |    60 | 17.6 |        
   21113 | 2022-09-05 17:20:06 |         MASTER-SAAO | (23h 00m 57.10s , -33d 13m 29.5s) |   C |    60 | 17.6 |        
   21196 | 2022-09-05 17:21:29 |         MASTER-SAAO | (22h 45m 20.59s , -35d 07m 28.2s) |   C |    60 | 18.3 |        
   21287 | 2022-09-05 17:23:01 |         MASTER-SAAO | (22h 55m 02.43s , -35d 08m 23.4s) |   C |    60 | 18.4 |        
   21463 | 2022-09-05 17:25:56 |         MASTER-SAAO | (22h 50m 13.38s , -31d 21m 29.9s) |   C |    60 | 18.2 |        
   21870 | 2022-09-05 17:32:43 |         MASTER-SAAO | (22h 42m 48.49s , -33d 13m 47.0s) |   C |    60 | 18.4 |        
   22163 | 2022-09-05 17:37:36 |         MASTER-SAAO | (22h 51m 19.35s , -33d 13m 37.9s) |   C |    60 | 18.3 |        
   22245 | 2022-09-05 17:38:58 |         MASTER-SAAO | (23h 00m 59.57s , -33d 14m 37.1s) |   C |    60 | 18.5 |        
   22338 | 2022-09-05 17:40:31 |         MASTER-SAAO | (22h 45m 14.95s , -35d 09m 35.5s) |   C |    60 | 18.7 |        
   22420 | 2022-09-05 17:41:53 |         MASTER-SAAO | (22h 55m 06.18s , -35d 09m 31.0s) |   C |    60 | 18.8 |        
   22607 | 2022-09-05 17:45:00 |         MASTER-SAAO | (22h 50m 14.90s , -31d 21m 29.0s) |   C |    60 | 18.5 |        
   23017 | 2022-09-05 17:51:50 |         MASTER-SAAO | (22h 42m 42.57s , -33d 13m 51.6s) |   C |    60 | 18.6 |        
   23324 | 2022-09-05 17:56:57 |         MASTER-SAAO | (22h 51m 17.95s , -33d 15m 51.9s) |   C |    60 | 18.7 |        
   23600 | 2022-09-05 18:01:33 |         MASTER-SAAO | (22h 55m 02.30s , -35d 09m 28.6s) |   C |    60 | 18.8 |        
   23774 | 2022-09-05 18:04:27 |         MASTER-SAAO | (22h 50m 09.71s , -31d 20m 56.2s) |   C |    60 | 18.4 |        
   23950 | 2022-09-05 18:07:23 |         MASTER-SAAO | (22h 42m 46.64s , -33d 14m 54.1s) |   C |    60 | 18.8 |        
   24258 | 2022-09-05 18:12:31 |         MASTER-SAAO | (22h 58m 38.98s , -31d 20m 17.1s) |   C |    60 | 18.4 |        
   24610 | 2022-09-05 18:18:23 |         MASTER-SAAO | (23h 03m 45.94s , -35d 09m 57.1s) |   C |    60 | 18.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220831A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32521
SUBJECT: GRB 220831A: Swift-UVOT Upper Limits
DATE:    22/09/05 22:06:27 GMT
FROM:    Noel Klingler at NASA-GSFC / UMBC  <njk5441@psu.edu>

N. J. Klingler (NASA-GSFC/UMBC/CRESST II) reports on behalf of the
Swift-UVOT team:

Swift-UVOT has performed follow-up observations of the Swift-BAT-detected
burst GRB 220831A (Tohuvavohu et al. GCN 32506), collecting 4.7 ks of
observations with the White filter between T0+51.2 ks and T0+78.8 ks.  No
source was detected in the UVOT data at the position of the X-ray source
reported by Dichiara et al. (GCN 32510), which is also positionally
coincident with the candidate near-infrared and optical counterparts
reported by D'Avanzo et al. (GCN 32513) and Freeburn et al. (GCN 32516),
respectively.

3-sigma upper limits using the UVOT photometric system (Breeveld et al.
2011, AIP Conf. Proc. 1358, 373) are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag
white           51227          78844        4712         >23.39

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.0161684 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB220907A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32525
SUBJECT: GRB 220907A: Fermi GBM Final Real-time Localization
DATE:    22/09/07 14:15:57 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 14:05:26 UT on 7 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220907A (trigger 684252331.480966 / 220907587).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 269.6, Dec = -18.7 (J2000 degrees, equivalent to J2000 17h 58m, -18d 41'), with a statistical uncertainty of 6.9 degrees.

The angle from the Fermi LAT boresight is 75.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220907587/quicklook/glg_skymap_all_bn220907587.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220907587/quicklook/glg_healpix_all_bn220907587.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220907587/quicklook/glg_lc_medres34_bn220907587.gif


GRB_name: GRB220907A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32526
SUBJECT: GRB 220907A: Swift detection of a burst
DATE:    22/09/07 14:24:33 GMT
FROM:    Kim Page at U.of Leicester  <kimlpage1978@gmail.com>

K. L. Page (U Leicester), P. A. Evans (U Leicester),
R. A. J. Eyles-Ferris (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. J. Klingler (GSFC/UMBC/CRESSTII),
H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
B. Sbarufatti (INAF-OAB), M. H. Siegel (PSU),
A. Tohuvavohu (U Toronto) and M. A. Williams (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 14:05:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220907A (trigger=1123129).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 268.870, -20.315 which is 
   RA(J2000) = 17h 55m 29s
   Dec(J2000) = -20d 18' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex peak
structure with a duration of about 20 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 14:06:56.5 UT, 90.7 seconds after
the BAT trigger. No source was detected in 188 s of promptly downlinked
data. We are waiting for the full dataset to detect and localise the
XRT counterpart. 

No prompt UVOT data products are available. 

Although there is no counterpart found in the (short) XRT exposure,
the high significance of the BAT detection (8.5 sigma) and the
simultaneous detection by Fermi/GBM (GCN #32525)
indicates that this is an astrophysical event. 

Burst Advocate for this burst is K. L. Page (kimlpage1978 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: GRB220907A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32527
SUBJECT: GRB 220907A: Swift-XRT position
DATE:    22/09/07 17:09:56 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

K. L. Page and P. A. Evans (U Leicester) reports on behalf of the
Swift-XRT team:

We have analysed 678 s of XRT data for GRB 220907A (Page et al. GCN Circ.
32526), from 74 s to 4.1 ks after the BAT trigger. An X-ray source is now
detected within the BAT error circle. The refined XRT position is RA, Dec
= 268.8714, -20.2879 which is equivalent to:

RA (J2000): 17 55 29.14
Dec(J2000): -20 17 16.6

with an uncertainty of 5.0 arcsec (radius, 90% confidence).

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


GRB_name: GRB220831A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32529
SUBJECT: GRB 220831A: ATCA 5/9 GHz radio observations
DATE:    22/09/08 02:40:23 GMT
FROM:    Gemma Anderson at Curtin U  <gemma.anderson@curtin.edu.au>

G. E. Anderson (Curtin), M. E. Bell (UNewcastle), P. J. Hancock (Curtin),
J. C. A. Miller-Jones (Curtin), M. D. Aksulu (UvA), A. Bahramian (Curtin),
A. J. van der Horst (GWU), S. D. Ryder (Macquarie), A. Rowlinson (UvA, ASTRON),
R. A. M. J. Wijers (UvA)

We used the Australia Telescope Compact Array (ATCA) to perform a radio
observation of the short GRB 220831A at 5.5 and 9 GHz. The scheduled observations
began on 2022 Sept 14 UT for 5 hours (4 days post-burst; Fermi GBM Team
GCN 32511, which had been localised by Swift/BAT-GUANO; A. Tohuvavohu et al.,
GCN 32506). No radio source was detected at the candidate Swift-XRT, VLT/HAWK-I
and DECam afterglow position (S. Dichiara et al., GCN 32510; P. Dâ€™Avanzo et al.,
GCN 32513; A. Moller et al., GCN 32516), with 3 sigma upper-limits of 39 microJy
and 36 microJy at 5.5 and 9 GHz, respectively.

We thank the ATCA and CSIRO Astronomy and Space Science (CASS) staff for
scheduling these observations.


Gemma Anderson
Senior Research Fellow | Curtin Institute of Radio Astronomy (CIRA)
International Centre for Radio Astronomy Research (ICRAR)
My work days are Monday, Wednesday, Thursday and Friday

Curtin University
Tel | +61 8 9266 3785
Email | gemma.anderson@curtin.edu.au<mailto:gemma.anderson@curtin.edu.au>
Pronouns | She/Her

[signature_930817360]

CRICOS Provider Code 00301J


GRB_name: GRB220907A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32530
SUBJECT: GRB 220907A: Swift-XRT refined Analysis
DATE:    22/09/08 07:04:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K. L. Page (U Leicester) reports on behalf of the Swift-XRT team:

We have analysed 5.6 ks of XRT data for GRB 220907A (Page et al. GCN
Circ. 32526), from 100 s to 21.5 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. Using 188 s of PC mode data
and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 268.87315, -20.28950 which is equivalent to:

RA (J2000): 17h 55m 29.56s
Dec(J2000): -20d 17' 22.2"

with an uncertainty of 4.0 arcsec (radius, 90% confidence). The source
is fading with alpha >0.4.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01123129.

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


GRB_name: GRB220907A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32531
SUBJECT: GRB 220907A: Swift/UVOT Upper Limits
DATE:    22/09/08 12:26:27 GMT
FROM:    Samantha Oates at MSSL  <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U. Birmingham) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220907A
95 s after the BAT trigger (Page et al., GCN Circ. 32526).
No optical afterglow consistent with the enhanced XRT position
(Page and Evans GCN Circ. 32530)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            95          245          147         >20.2
white               95         5001          298         >20.6
v                 3823         4023          197         >18.6
b                 4644         4844          197         >19.7
u                 4438         4638          197         >19.4
w1                4234         4433          197         >19.2
m2                4028         4228          197         >19.2
w2                3618         3818          197         >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.637 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB220907A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32532
SUBJECT: GRB 220907A: Nanshan/NEXT optical upper limits 
DATE:    22/09/08 13:04:59 GMT
FROM:    Zipei Zhu at NAOC  <zpzhu@nao.cas.cn>

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

We observed the field of GRB 220907A detected by Swift (Page et al., GCN 32526) and Fermi/GBM (GCN 32525) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained a series of frames in the Sloan r-band and Sloan z-band, starting at 14:07:13 UT on 2022-09-07, i.e., 108s after the BAT trigger.

No uncatalogued optical source is detected in our stacked images at the XRT position (Page eta al., GCN32527), with upper limits as follows:

T_mid-T0 (min)    Filter   Upper limit(3-sigma)
    15.5                 r          >19.5
    34.5                 z          >18.1

calibrated with the nearby PanSTARRS field and not corrected for Galactic extinction.


GRB_name: GRB220907A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32533
SUBJECT: GRB 220907A: Fermi GBM observation
DATE:    22/09/08 14:27:54 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

S. Dalessi, C. Meegan and P. Veres (all UAH)
report on behalf of the Fermi GBM Team:

"At 14:05:26.48 UT on 07 September 2022, the Fermi Gamma-Ray Burst
Monitor (GBM) triggered and located GRB 220907A (trigger 684252331 /
220907587), which was also detected by the Swift/BAT (Page et al.
2022, GCN 32526, 32530). The Fermi GBM Final Real-time Localization
(GCN 32525) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 50 degrees.

The GBM light curve shows a single peak with a duration (T90) of about
9 s (50-300 keV). The time-averaged spectrum from T0-2.8 s to T0+5.4 s
is best fit by a power law function with index = -1.48 +/- 0.07.

The event fluence (10-1000 keV) in this time interval is (1.13 +/-
0.12)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from
T0+1.02 s in the 10-1000 keV band is 2.32 +/- 0.24 ph/s/cm^2.

A power law function with an exponential high-energy cutoff fits the
spectrum equally well.  The power law index is -1.01 +/- 0.29 and the
cutoff energy, parameterized as Epeak, is 320 +/- 170 keV and fluence
(1.02 +/-0.22)E-6 erg/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: GRB220903A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32534
SUBJECT: IPN triangulation of GRB 220903A (long)
DATE:    22/09/08 15:45:14 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, and C. Wilson-Hodge
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 220903A
has been detected by Fermi (GBM trigger 683900183),
INTEGRAL (SPI-ACS), Konus-Wind, and Swift (BAT), so far,
at about 44178 s UT (12:16:18).
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:
   178.795 (11h 55m 11s) -29.705 (-29d 42' 17")
  Corners:
   176.905 (11h 47m 37s) -30.818 (-30d 49' 04")
   177.561 (11h 50m 15s) -31.150 (-31d 09' 02")
   180.605 (12h 02m 25s) -28.545 (-28d 32' 44")
   179.962 (11h 59m 51s) -28.232 (-28d 13' 54")
  ---------------------------------------------
The error box area is 2.32 sq. deg, and its maximum
dimension is 3.94 deg (the minimum one is 37.6 arcmin).
The Sun distance was 39 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final localization (glg_healpix_all_bn220903511_v01).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220903_T44175/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.


GRB_name: GRB220831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32535
SUBJECT: GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
DATE:    22/09/08 16:56:10 GMT
FROM:    Charles Kilpatrick at Northwestern U  <ckilpatrick@northwestern.edu>

A. C. Gordon (Northwestern U.), N. Tejos (PUCV), and C. D. Kilpatrick (Northwestern U.) report on behalf of the F4 Collaboration:

"We observed the Swift/BAT-GUANO localization of GRB 220831A (Tohuvavohu et al., GCN #32506) with Gemini South/GMOS in follow-up to the DECam observation (Freeburn et al., GCN #32516). Imaging in r- and i-band were carried out starting at UT 2022-09-05 04:05:49.

We detect the source in i-band and an upper limit in r-band at the following position (coincident with GCN #32516) at the coordinates (J2000):

RA = 01:37:00.9864
Dec = -41:35:34.296

From this source, we measure magnitudes (AB mag):
r > 26.4
i = 25.69 +/- 0.31

Our observations confirm that the source presented in GCN #32516 has faded significantly, which supports the hypothesis that it was a transient source associated with GRB 220831A and its weak X-ray counterpart (Dichiara et al., GCN #32510)."


GRB_name: GRB220907A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32537
SUBJECT: GRB 220907A: Swift-BAT refined analysis
DATE:    22/09/08 20:58:07 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),  H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
T. Sakamoto (AGU), (i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220907A (trigger #1123129)
(Page, et al., GCN Circ.32526).  The BAT ground-calculated position is
RA, Dec = 268.869, -20.303 deg which is
   RA(J2000)  =  17h 55m 28.6s
   Dec(J2000) = -20d 18' 10.8"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 90%.
The mask-weighted light curve shows a single peak of ten seconds approximate
duration starting at T-1 sec.   A spacecraft maneuver took the source out of the BAT
field of view at approximately 400 seconds.  T90 (15-350 keV) is 8.49 +- 1.56 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.60 to T+10.29 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.99 +- 0.24.  The fluence in the 15-150 keV band is 4.1 +- 0.6 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.70 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1123129/BA/


GRB_name: GRB220909A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32539
SUBJECT: GRB 220909A: Fermi GBM Final Real-time Localization
DATE:    22/09/09 07:02:29 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 06:52:13 UT on 9 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220909A (trigger 684399138.822486 / 220909286).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 212.4, Dec = -17.7 (J2000 degrees, equivalent to J2000 14h 09m, -17d 41'), with a statistical uncertainty of 6.3 degrees.

The angle from the Fermi LAT boresight is 56.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220909286/quicklook/glg_skymap_all_bn220909286.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220909286/quicklook/glg_healpix_all_bn220909286.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220909286/quicklook/glg_lc_medres34_bn220909286.gif


GRB_name: GRB220910A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32540
SUBJECT: GRB 220910A: AGILE detection
DATE:    22/09/10 10:01:59 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

A. Ursi, E. Menegoni (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor
Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano,
G. Piano (INAF/IAPS), A. Bulgarelli, A. Di Piano, V. Fioretti, G.
Panebianco, N. Parmiggiani (INAF/OAS-Bologna), F. Lucarelli, C. Pittori, F.
Verrecchia (SSDC, and INAF/OAR), M. Romani (INAF/OA-Brera), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), F.
Longo (Univ. Trieste and INFN Trieste), and P. Tempesta (TeleSpazio),
report on behalf of the AGILE Team:

The AGILE satellite detected the GRB 220910A at T0 = 2022-09-10 05:48:26 s
(UTC). The burst is clearly visible in the AGILE scientific ratemeters of
the MiniCALorimeter (MCAL; 0.4-100 MeV) and AntiCoincidence (AC; 50-200
keV) detectors. The event lasted about 3 s and it released a total number
of 8416 counts in the MCAL detector (above a background rate of 1310 Hz)
and 25992 counts in the AC detector (above a background rate of 4830 Hz).
The AGILE ratemeters light curves can be found at
http://www.agilescienceapp.it/notices/GRB220910A_AGILE_RM.png .

Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert
Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.


GRB_name: GRB220910A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32541
SUBJECT: GRB 220910A: AstroSat CZTI detection
DATE:    22/09/10 19:34:14 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

R. Gopalakrishnan (IUCAA), V. Prasad (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 bright long GRB 220910A 
which was also detected by AGILE (Ursi et al., GCN 32540) and reported 
in an IPN_RAW notice (by Konus-Wind).

The source was clearly detected in the 20-200 keV energy range. The 
light curve showed multiple peaks of emission with the strongest peak at 
2022-09-10 05:48:29.0 UTC. The measured peak count rate associated with 
the burst is 4111 (+341, -343) counts/s above the background in the 
combined data of all quadrants, with a total of 5809 (+205, -203) 
counts. The local mean background count rate was 503 (+6, -11) counts/s. 
Using cumulative rates, we measure a T90 of 2.6 (+0.4, -0.3) s.

It was also clearly detected in the CsI anticoincidence (Veto) detector 
in the 100-500 keV energy range. The light curve peaks at 2022-09-10 
05:48:27.0 UTC. The measured peak count rate is 6301 (+143, -155) 
counts/s above the background in the combined Veto data of all 
quadrants, with a total of 14603 (+414, -431) counts. The local mean 
background count rate was 1477 (+7, -8) counts/s. We measure a T90 of 
3.7 (+0.5, -0.6) s from the cumulative Veto light curve.

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


GRB_name: GRB220831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32542
SUBJECT: GRB 220831A: Gemini-South Infrared Observations
DATE:    22/09/10 20:56:20 GMT
FROM:    Brendan O'Connor at UMD  <oconnorb@umd.edu>

B. O'Connor (UMD/GWU), E. Troja (UTV/ASU), S. Dichiara (PSU),
on behalf of a larger collaboration:

We performed target of opportunity observations of GRB 220831A
(Tohuvavohu et al. GCN 32506) with the FLAMINGOS-2 spectrograph
mounted on the Gemini-South telescope. Observations were taken
in the J and Ks filters with total exposure of 1785 and 1635 s,
respectively. The observations began at 2022-09-09 03:27:01 UT,
corresponding to ~8.6 d after the burst. Further observations
were obtained the following night (~9.6 d) in J-band for
2000 s exposure.

At the location of the optical, infrared, and X-ray counterpart
(Dichiara et al. GCN 32510, D'Avanzo et al. GCN 32513, Freeburn
et al. GCN 32516, Gordon et al. GCN 32535), we detect a faint
source with brightness J ~ 24.5 AB mag. This result confirms the
fading of the infrared source reported by D'Avanzo et al.
GCN 32513.

Our measurement implies a very red color, r-J >2, of the late
time emission. At present it is not clear whether this is due
to the onset of a kilonova or to the contribution of an underlying
host galaxy. Assuming a behavior similar to AT2017gfo, the
apparent J-band magnitude implies a distance of ~200 Mpc. However,
the nearby galaxy noted by Dâ€™Avanzo et al. GCN 32513 is significantly
closer at only 4 Mpc.

If instead the source is dominated by the host galaxy contribution,
the red color suggests that GRB 220831A was a distant event
(see, e.g., O'Connor et al. 2022, MNRAS, 515, 4890).

Further observations are planned.

Magnitudes are calibrated against stars in the 2MASS catalog
and are not corrected for Galactic extinction.

We thank the staff of the Gemini Observatory, in particular
Joan Font-Serra and Yijung Kang, for rapid scheduling of
these observations.


GRB_name: GRB220909A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32543
SUBJECT: GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
DATE:    22/09/11 16:22:58 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

Gayathri Raman (PSU), James DeLaunay (UAlabama), Aaron Tohuvavohu (U
Toronto), Jamie A. Kennea (PSU), report:

Swift/BAT did not localize GRB 220909A onboard (T0: 2022-09-09T06:52:13
 UTC, Fermi/GBM GCN 32539).

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, 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,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 8.9 in a 4.096
s analysis time bin.

NITRATES results, independently, are ambiguous with respect to whether
this burst originates from in or outside the BAT FOV, with a
borderline DeltaLLHOut of 6.7 and a marginally preferred arcminute
location with DeltaLLHPeak of 2.

See Section 9.1 and Figure 20 in the NITRATES paper for brief
descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and
DeltaLLHOut.

The BAT candidate position is
RA, Dec = 216.0448, -8.8551 deg which is
   RA(J2000)  = 14h 24m 10.75s
   Dec(J2000) = -8d 51â€² 18.4â€³
with an estimated uncertainty of 3 arcmin.

This position is consistent with the Fermi/GBM localization (GCN 32539).
Independent spectral and/or fluence measurements of this burst from
other instruments could help determine the preferred spatial origin.

XRT and UVOT follow-up has been requested.
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: GRB220909A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32544
SUBJECT: GRB 220909A: Swift ToO observations
DATE:    22/09/11 19:01:12 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 220909A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021513

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-GUANO 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: GRB220905A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32545
SUBJECT: IPN triangulation of GRB 220905A
DATE:    22/09/11 20:08:57 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
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 220905A
(Fermi-GBM detection: Fermi GBM Team, GCN Circ. 32518,
BALROG localization: Biltzinger et al., GCN Circ. 32519)
was detected by Fermi (GBM trigger 684070128),
INTEGRAL (SPI-ACS), Konus-Wind, and Swift (BAT)
at about 41324 s UT (11:28:44).
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:
   338.931 (22h 35m 43s) -37.594 (-37d 35' 38")
  Corners:
   341.100 (22h 44m 24s) -39.495 (-39d 29' 42")
   341.797 (22h 47m 11s)  +6.185 ( +6d 11' 06")
   336.870 (22h 27m 29s) -35.655 (-35d 39' 18")
   289.822 (19h 19m 17s) -23.843 (-23d 50' 36")
  ---------------------------------------------
The error box area is 349.6 sq. deg, and its maximum
dimension is 87.7 deg (the minimum one is 5 deg).
The Sun distance was 125 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of, the
Fermi GBM Final Real-time position (GCN Circ. 31955) and BALROG
(GCN 31950) localizations.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220905_T41330/IPN

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


GRB_name: GRB220912A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32546
SUBJECT: GRB 220912A: Fermi GBM Final Real-time Localization
DATE:    22/09/12 01:00:39 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 00:50:21 UT on 12 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220912A (trigger 684636626.526236 / 220912035).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 165.3, Dec = 49.3 (J2000 degrees, equivalent to J2000 11h 01m, 49d 17'), with a statistical uncertainty of 3.6 degrees.

The angle from the Fermi LAT boresight is 81.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220912035/quicklook/glg_skymap_all_bn220912035.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220912035/quicklook/glg_healpix_all_bn220912035.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220912035/quicklook/glg_lc_medres34_bn220912035.gif


GRB_name: GRB220909A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32547
SUBJECT: GRB 220909A: Swift-XRT observations
DATE:    22/09/12 05:51:40 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC &
INAF-OAR), 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) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 220909A, collecting 5.5 ks of Photon
Counting (PC) mode data between T0+216.5 ks and T0+235.1 ks. 

One uncatalogued X-ray source has been detected consistent with being
within 296 arcsec of the Swift/BAT-GUANO position (Raman et al, GCN
Circ. 32543), it is below the RASS limit and shows no definitive signs
of fading. Therefore, at the present time we cannot confirm this as the
afterglow. Details of this source are given below:

Source 5:
  RA (J2000):  216.0407  =  14:24:9.76
  Dec (J2000): -8.8439  =  -08:50:37.9
  Error: 7.3 arcsec (radius, 90% conf.)
  Count-rate: (1.12 [+0.72, -0.53])e-3 ct s^-1  
  Distance: 43 arcsec from Swift/BAT-GUANO position.

Seven uncatalogued sources were also detected too far from the GRB
position to be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021513.

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


GRB_name: GRB220831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32548
SUBJECT: GRB 220831A: DECam optical counterpart follow-up 
DATE:    22/09/12 07:33:12 GMT
FROM:    Anais Moller at Australian National U  <anais.moller@anu.edu.au>

GRB 220831A: DECam optical counterpart follow-up





J. Freeburn, N. Van Bemmel, D. Dobie, A. Moller, J. Cooke (Swinburne/OzGrav), M. Suhr (Swinburne/ASTRO 3D), S. Webb (Swinburne) report on behalf of the Deeper, Wider, Faster Collaboration





We have carried out additional observations further to GCN 32516 of the optical counterpart (RA = 01:37:0.965, DEC = -41:35:34.60) to GRB220831A (GCN 32506). Here we present source observations using the Dark Energy Camera (DECam) on the V. M. Blanco 4-m telescope and revised, forced photometry of our previous observations using NOAO calibrated images. Images were taken in g, r, i on UT dates 2022-08-31 to 2022-09-04 as additional observations during the Deeper, Wider, Faster (DWF) program observing run.





Our photometry, along with those of Gordon et al. (GCN 32535) and D'Avanzo et al. (GCN 32513) are consistent with current short GRB optical afterglow models.





The following detection and upper limits (not corrected for Galactic extinction):





T-start (MJD)    filter          detection/UL

59823.200            g             23.17 +/- 0.18

59823.203            r              22.885 +/- 0.088

59823.209            i              23.06 +/- 0.13

59823.384            g             23.72 +/- 0.30

59823.395            r              23.37 +/- 0.13

59823.389            i              23.12     +/- 0.13

59824.198            g             24.33 +/- 0.37

59824.203            r              24.69 +/- 0.35

59824.208            i              23.86 +/- 0.22

59824.377            g             24.94 +/- 0.59

59824.390            r              24.13 +/- 0.25

59824.391            i              24.10 +/- 0.25

59825.300            r              >24.8

59825.301            i              >24.4

59826.306            i              >25.0


GRB_name: GRB220912A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32549
SUBJECT: GRB 220912A: AstroSat CZTI detection
DATE:    22/09/12 18:06:24 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

R. Gopalakrishnan (IUCAA), V. Prasad (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 a weak detection of a long GRB 220912A which 
was also detected by Fermi GBM (GCN 32546).

The source was clearly detected in the 20-200 keV energy range. The 
light curve peaks at 2022-09-12 00:50:39.3 UTC. The measured peak count 
rate associated with the burst is 294 (+173, -15) counts/s above the 
background in the combined data of all quadrants, with a total of 1224 
(+364, -386) counts. The local mean background count rate was 444 (+3, 
-4) counts/s. Using cumulative rates, we measure a T90 of 26 (+7, -7) s.

It was also detected in the CsI anticoincidence (Veto) detector in the 
100-500 keV energy range. The light curve peaks at 2022-09-12 00:50:25.0 
UTC. The measured peak count rate is 188 (+76, -25) counts/s above the 
background in the combined Veto data of all quadrants, with a total of 
1476 (+545, -575) counts. The local mean background count rate was 1458 
(+3, -4) counts/s. We measure a T90 of 24 (+14, -12) s from the 
cumulative Veto light curve.

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


GRB_name: GRB220910A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32550
SUBJECT: IPN triangulation of GRB 220910A (bright/long)
DATE:    22/09/12 19:14:14 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, and C. Wilson-Hodge
on behalf of the Fermi GBM team,

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

The very bright, long-duration GRB 220910A
(AGILE detection: Ursi et al., GCN Circ. 32540;
AstroSat-CZTI detection: Gopalakrishnan et al., GCN Circ. 32541)
was detected by AGILE (MCAL, AC), AstroSat (CZTI), Konus-Wind,
Fermi (GBM trigger 684481706), and INTEGRAL (SPI-ACS),
at about 20910 s UT (05:48:30).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
     8.124 (00h 32m 30s)  -0.115 ( +0d 06' 55")
  Corners:
     9.094 (00h 36m 23s)  -2.392 ( -2d 23' 30")
     7.404 (00h 29m 37s)  +2.183 ( +2d 11' 01")
     7.046 (00h 28m 11s)  +2.146 ( +2d 08' 44")
     8.743 (00h 34m 58s)  -2.426 ( -2d 25' 32")
  ---------------------------------------------
The error box area is 1.68 sq. deg, and its maximum
dimension is 4.98 deg (the minimum one is 20.6 arcmin).
The Sun distance was 160 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final localization (glg_healpix_all_bn220910242_v00).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220910_T20910/IPN/

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


GRB_name: GRB220910A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32551
SUBJECT: GRB 220910A: Fermi GBM observation
DATE:    22/09/12 19:17:35 GMT
FROM:    Christian Malacaria at ISSI  <cmalacaria.astro@gmail.com>

C. Malacaria (ISSI) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 05:48:21.55 UT on 10 September 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220910A (trigger 684481706 / 220910242),
which was also detected by AGILE (Ursi et al. 2022, GCN 32540)
and AstroSAT/CZTI (Gopalakrishnan et al. 2022, GCN 32541).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 9.1, Dec = -1.1 (J2000 degrees, equivalent to
J2000 00h 32m, -01d 06'), with a statistical uncertainty of 1.0 degrees
(radius, 1-sigma containment, statistical only; 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 at the GBM trigger time is 89 degrees.

The GBM light curve shows a precursor and a main, subsequent peak
with a duration (T90) of about 4 s (50-300 keV).
The time-averaged spectrum from T0-4.5 s to T0+10.6 s is
best fit by a Band function with Epeak = 357 +/- 8 keV,
alpha = -0.69 +/- 0.01, and beta = -2.51 +/- 0.06

The event fluence (10-1000 keV) in this time interval is
(4.69 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+6.85 s in the 10-1000 keV band
is 76.9 +/- 0.6 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  <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/  <https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/>"


GRB_name: GRB220912A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32552
SUBJECT: Fermi GRB 220912A: Global MASTER-Net observations report 
DATE:    22/09/12 20:30:14 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220912A ( Fermi GBM team, GCN 32546) errorbox  46550 sec after notice time and 46582 sec after trigger time at 2022-09-12 13:46:44 UT, with upper limit up to  14.6 mag. The observations began at zenith distance = 68 deg. The sun  altitude  is -20.8 deg. 

MASTER-Amur robotic telescope  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 220912A errorbox  61578 sec after notice time and 61609 sec after trigger time at 2022-09-12 17:57:11 UT, with upper limit up to  18.1 mag. The observations began at zenith distance = 71 deg. The sun  altitude  is -27.0 deg. 

The galactic latitude b = 60 deg., longitude l = 159 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2085906

We obtain a following upper limits.  

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

   46613 | 2022-09-12 13:46:44 |        MASTER-Tunka | (11h 30m 19.04s , +51d 47m 40.5s) |   C |    60 | 12.9 |  Coadd 
   46891 | 2022-09-12 13:51:22 |        MASTER-Tunka | (10h 44m 51.56s , +53d 41m 35.0s) |   C |    60 | 13.4 |  Coadd 
   46963 | 2022-09-12 13:52:34 |        MASTER-Tunka | (10h 57m 53.18s , +53d 41m 23.3s) |   C |    60 | 14.1 |  Coadd 
   47107 | 2022-09-12 13:54:58 |        MASTER-Tunka | (10h 31m 13.89s , +51d 47m 13.7s) |   C |    60 | 12.6 |  Coadd 
   47176 | 2022-09-12 13:56:07 |        MASTER-Tunka | (11h 27m 13.06s , +49d 53m 32.7s) |   C |    60 | 13.2 |  Coadd 
   48696 | 2022-09-12 14:21:27 |        MASTER-Tunka | (11h 09m 52.80s , +53d 40m 36.9s) |   C |    60 | 14.6 |  Coadd 
   49713 | 2022-09-12 14:38:24 |        MASTER-Tunka | (11h 10m 04.22s , +53d 41m 10.4s) |   C |    60 | 13.5 |  Coadd 
   61640 | 2022-09-12 17:57:11 |         MASTER-Amur | (10h 32m 13.61s , +50d 34m 51.9s) |   C |    60 | 17.5 |        
   61799 | 2022-09-12 17:59:50 |         MASTER-Amur | (10h 34m 00.94s , +52d 29m 12.7s) |   C |    60 | 17.4 |        
   62606 | 2022-09-12 18:13:17 |         MASTER-Amur | (10h 32m 12.78s , +50d 35m 30.8s) |   C |    60 | 17.7 |        
   62766 | 2022-09-12 18:15:57 |         MASTER-Amur | (10h 34m 03.10s , +52d 29m 29.0s) |   C |    60 | 17.5 |        
   63573 | 2022-09-12 18:29:24 |         MASTER-Amur | (10h 32m 19.72s , +50d 34m 21.7s) |   C |    60 | 17.7 |        
   63732 | 2022-09-12 18:32:03 |         MASTER-Amur | (10h 34m 01.14s , +52d 28m 09.2s) |   C |    60 | 17.5 |        
   64017 | 2022-09-12 18:36:48 |         MASTER-Amur | (10h 42m 09.66s , +48d 42m 07.2s) |   C |    60 | 17.7 |        
   64097 | 2022-09-12 18:38:08 |         MASTER-Amur | (10h 54m 24.03s , +48d 41m 15.9s) |   C |    60 | 17.9 |        
   64256 | 2022-09-12 18:40:47 |         MASTER-Amur | (10h 31m 18.69s , +48d 41m 24.4s) |   C |    60 | 17.6 |        
   64814 | 2022-09-12 18:50:05 |         MASTER-Amur | (10h 41m 33.50s , +46d 46m 46.3s) |   C |    60 | 17.7 |        
   65101 | 2022-09-12 18:54:52 |         MASTER-Amur | (10h 53m 20.72s , +46d 46m 39.3s) |   C |    60 | 17.7 |        
   65181 | 2022-09-12 18:56:12 |         MASTER-Amur | (10h 42m 12.38s , +48d 39m 29.2s) |   C |    60 | 17.8 |        
   65262 | 2022-09-12 18:57:33 |         MASTER-Amur | (10h 54m 24.51s , +48d 39m 58.8s) |   C |    60 | 18.0 |        
   65422 | 2022-09-12 19:00:13 |         MASTER-Amur | (10h 31m 19.64s , +48d 39m 27.7s) |   C |    60 | 17.8 |        
   65987 | 2022-09-12 19:09:38 |         MASTER-Amur | (10h 41m 38.49s , +46d 46m 49.5s) |   C |    60 | 18.1 |        
   66271 | 2022-09-12 19:14:22 |         MASTER-Amur | (10h 53m 21.02s , +46d 47m 01.2s) |   C |    60 | 17.8 |        
   66352 | 2022-09-12 19:15:43 |         MASTER-Amur | (10h 42m 11.01s , +48d 40m 03.2s) |   C |    60 | 17.8 |        
   66431 | 2022-09-12 19:17:02 |         MASTER-Amur | (10h 54m 17.82s , +48d 41m 12.0s) |   C |    60 | 18.1 |        
   66591 | 2022-09-12 19:19:42 |         MASTER-Amur | (10h 31m 18.77s , +48d 38m 46.0s) |   C |    60 | 17.7 |        
   67162 | 2022-09-12 19:29:13 |         MASTER-Amur | (10h 41m 42.28s , +46d 45m 42.4s) |   C |    60 | 17.9 |        
   67242 | 2022-09-12 19:30:33 |         MASTER-Amur | (10h 53m 17.00s , +46d 44m 52.0s) |   C |    60 | 17.8 |        
   67321 | 2022-09-12 19:31:52 |         MASTER-Amur | (11h 03m 12.57s , +44d 52m 42.4s) |   C |    60 | 17.7 |        
   67401 | 2022-09-12 19:33:12 |         MASTER-Amur | (11h 14m 29.50s , +44d 51m 35.6s) |   C |    60 | 17.7 |        
   67481 | 2022-09-12 19:34:32 |         MASTER-Amur | (11h 26m 00.47s , +46d 46m 14.3s) |   C |    60 | 17.3 |        
   67641 | 2022-09-12 19:37:12 |         MASTER-Amur | (10h 41m 43.54s , +44d 50m 31.7s) |   C |    60 | 18.0 |        
   67720 | 2022-09-12 19:38:31 |         MASTER-Amur | (10h 53m 07.37s , +44d 50m 43.7s) |   C |    60 | 17.8 |        
   68278 | 2022-09-12 19:47:49 |         MASTER-Amur | (11h 03m 13.50s , +44d 50m 59.7s) |   C |    60 | 17.3 |        
   68357 | 2022-09-12 19:49:09 |         MASTER-Amur | (11h 14m 32.84s , +44d 52m 42.4s) |   C |    60 | 17.2 |        
   68437 | 2022-09-12 19:50:28 |         MASTER-Amur | (11h 26m 00.73s , +46d 45m 52.5s) |   C |    60 | 16.9 |        
   68596 | 2022-09-12 19:53:07 |         MASTER-Amur | (10h 41m 48.74s , +44d 51m 09.5s) |   C |    60 | 17.2 |        
   68676 | 2022-09-12 19:54:27 |         MASTER-Amur | (10h 53m 01.76s , +44d 50m 18.7s) |   C |    60 | 17.1 |        
   69239 | 2022-09-12 20:03:50 |         MASTER-Amur | (11h 03m 16.84s , +44d 51m 14.5s) |   C |    60 | 16.0 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220910B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32554
SUBJECT: GRB 220910B: Fermi GBM Final Localization
DATE:    22/09/13 14:05:58 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

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

At 15:02:57.88 UT on 10 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220910B (trigger 684514982 / 220910627).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 276.7, Dec = -53.5 (J2000 degrees, equivalent to J2000 18h 27m, -53d 30'), with a statistical uncertainty of 21.0 degrees.

The angle from the Fermi LAT boresight is 120.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220910627/quicklook/glg_skymap_all_bn220910627.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220910627/quicklook/glg_healpix_all_bn220910627.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220910627/quicklook/glg_lc_medres34_bn220910627.gif


GRB_name: GRB220910A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32555
SUBJECT: Konus-Wind detection of GRB 220910A
DATE:    22/09/13 15:16:11 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

The very bright, long-duration GRB 220910A
(AGILE detection: Ursi et al., GCN Circ. 32540;
AstroSat-CZTI detection: Gopalakrishnan et al., GCN Circ. 32541;
IPN triangulaton: Svinkin et al., GCN Circ. 32550;
Fermi-GBM observation: Malacaria and Meegan, GCN Circ. 32551)
triggered Konus-Wind at T0=20910.521 s UT (05:48:30.521).

The burst light curve shows a multipeaked structure
which starts at ~T0-5.7 s and has a total duration of ~13.4 s.
The emission is seen up to ~16 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220910_T20910/

As observed by Konus-Wind, the burst
had a fluence of 5.23(-0.50,+0.53)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.112 s,
of 3.93(-0.47,+0.49)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+10.496 s)
is best fit in the 20 keV - 16 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.53(-0.14,+0.17),
the high energy photon index beta = -2.46(-0.29,+0.19),
the peak energy Ep = 310(-37,+39) keV
(chi2 = 110/97 dof).

The spectrum near the maximum count rate
(measured from T0+1.280 to T0+2.304 s)
is best fit in the 20 keV - 16 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.21(-0.19,+0.25),
the high energy photon index beta = -2.61(-0.27,+0.19),
the peak energy Ep = 254(-29,+30) keV
(chi2 = 72/59 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB220909A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32556
SUBJECT: GRB 220909A: Fermi GBM observation
DATE:    22/09/14 13:30:13 GMT
FROM:    Christian Malacaria at ISSI  <cmalacaria.astro@gmail.com>

C. Malacaria (ISSI) and C. Meegan (UAH) 
report on behalf of the Fermi GBM Team:

"At 06:52:13.82 UT on 9 September 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220909A (trigger 684399138 / 220909286),
which was also detected by Swift/GUANO (Raman et al. 2022, GCN 32543).
The Fermi GBM Final Real-time Localization (GCN 32539) is consistent 
with the Swift-BAT GUANO position.

The angle from the Fermi LAT boresight at the GBM trigger time is 46 degrees.

The GBM light curve shows a peak
with a duration (T90) of about 14.6 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+6.7 s is
best fit by a power law function with an exponential
high-energy cutoff.
The power law index is -0.8 +/- 0.2  and
the cutoff energy, parameterized as Epeak, is 154 +/- 25 keV.

The event fluence (10-1000 keV) in this time interval is
(1.4 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.69 s in the 10-1000 keV band
is 3.6 +/- 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: GRB220910A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32559
SUBJECT: Improved IPN error box for GRB 220910A
DATE:    22/09/15 18:42:48 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, and C. Wilson-Hodge
on behalf of the Fermi GBM team,

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

Using the BepiColombo (MGNS) data we have
triangulated GRB 220910A (GCNs 32540, 32541, 32550, 32551, 32555)
to an improved 3 sigma error box whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
     8.734 (00h 34m 56s)  -1.848 ( -1d 50' 54")
  Corners:
     8.884 (00h 35m 32s)  -1.753 ( -1d 45' 11")
     9.042 (00h 36m 10s)  -2.231 ( -2d 13' 53")
     8.584 (00h 34m 20s)  -1.943 ( -1d 56' 35")
     8.411 (00h 33m 39s)  -1.432 ( -1d 25' 53")
  ---------------------------------------------
The error box area is 646 sq. arcmin, and its maximum
dimension is 1.019 deg (the minimum one is 19.44 arcmin).
The Sun distance was 159 deg.

This box may be further improved.

An updated triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220910_T20910/IPN/


GRB_name: GRB220921A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32567
SUBJECT: GRB 220921A: Tiled Swift observations
DATE:    22/09/21 18:43:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 220921A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00107

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/LAT event is high: 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: GRB220921A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32568
SUBJECT: GRB 220921A: Fermi-LAT detection
DATE:    22/09/21 19:17:34 GMT
FROM:    Roberta Pillera at Politecnico and INFN Bari  <roberta.pillera@ba.infn.it>

R. Pillera (Politecnico and INFN Bari), E. Bissaldi (Politecnico and 
INFN Bari),
N. Di Lalla (Stanford Univ.) report on behalf of the Fermi-LAT team:

At 11:05:59.07 UTC on September, 21, 2022 Fermi-LAT detected high-energy 
emission from GRB 220921A,
which was also detected by Fermi GBM (trigger 685451164 / 220921462).

The best LAT on-ground location is found to be

RA, Dec = 66.79, -40.25 (J2000)

with an error radius of 0.42 deg (90 % containment, statistical error 
only).
This was 69 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase in the event 
rate
that is spatially and temporally correlated with the trigger with high 
significance.
The 100 MeV - 1 GeV photon flux in the time interval 0-2000 s after the 
GBM trigger
is (3.1 +/- 0.1)E-06 ph/cm2/s.
The estimated photon index above 100 MeV is -2.1 +/- 0.3.
The highest-energy photon is a 866 MeV event which is observed 935 
seconds after the GBM trigger.

A Swift ToO has been requested for this burst.

The Fermi-LAT point of contact for this burst is
Roberta Pillera (roberta.pillera@ba.infn.it).

The Fermi-LAT is a pair conversion telescope designed to cover the 
energy band
from 20 MeV to greater than 300 GeV. It is the product of an
international collaboration between NASA and DOE in the U.S.
and many scientific institutions across France, Italy, Japan and Sweden.


GRB_name: GRB220921A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32570
SUBJECT: GRB 220921A: MASTER OT inside Fermi-LAT error-box
DATE:    22/09/21 22:44:10 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V.Lipunov (Lomonosov MSU), D.A.H.Buckley (SAAO),
N.Tiurina, A.Kuznetsov, O.Gress, E.Gorbovskoy, G.Antipov,
P.Balanutsa, K.Zhirkov, A.Chasovnikov, D.Vlasenko, V.Senik, D.Kuvshinov,
V.Topolev,Ya.Kechin, Yu.Tselik (Lomonosov Moscow State University, SAI, Physics Department),
C.Francile, R. Podesta, C.Lopez, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.Corella,
L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
N.M.Budnev (ISU,API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University)

MASTER OT J042553.42-402420.7 discovery as possibly counterpart of GRB 220921A
AT2022vjw

MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L )
  discovered OT source at (RA, Dec) = 04h 25m 53.42s -40d 24m 20.7s on 
2022-09-21.82255 UT during Fermi trigger 685451164 inspection(T0=2022-09-21 11:05:59.07) 
(Lipunov et al. GCN 32569, Fermi-LAT GCN 32568, also detected by GECAM-B)
https://master.sai.msu.ru/site/master2/event.php?id=2097239  .

The OT unfiltered magnitude is 17.8m (automatic), mlim=19.8.

The OT is seen in 24 images. There is no minor planet at this place.

We have 600 reference images without any OT since 2014, for ex., on 
2018-11-12.98741 UT with  unfiltered mlim=20.3m.

Spectral observations are required.

There is possible host galaxy in VIZIER database (DES, rmag=24.3)

The message may be cited.


GRB_name: GRB220921A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32571
SUBJECT: GRB 220921A: Swift-XRT Observations
DATE:    22/09/22 02:55:44 GMT
FROM:    Noel Klingler at NASA-GSFC / UMBC  <njk5441@psu.edu>

Swift-XRT has performed follow-up observations of the Fermi-LAT-detected
burst GRB 220921A, collecting 4.1 ks of Photon Counting (PC) mode data
between T0+27.4 and T0+40.7 ks.

An uncatalogued X-ray source has been detected consistent with being within
17.3 arcmin from the center of the Fermi-LAT position (which is within its
90% error radius of 25.19 arcmin; Pillera et al., GCN 32568), and being
consistent with the optical transient detected by MASTER (Lipunov et al.,
GCN 32570).  The source's peak flux (8.6 (+/- 1.9) * 10^-12 erg cm^-2 s^-1)
is 7.6-Ïƒ above the RASS limit, and it is fading with 2.9-Ïƒ significance.

Source 1:
  RA (J2000):  66.47255  =  04:25:53.41
  Dec (J2000): -40.4057  =  -40:24:20.4
  Error: 3.8 arcsec (radius, 90% conf.)
  Count-rate: (0.20 [+/- 0.04]) ct s^-1
  Distance: 17.3 arcsec from Fermi-LAT position
  Exposure: 1328 s (vignetting corrected)

Two other uncatalogued sources were also detected within the GRB position.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/xrt_products/TILED_GRB00107/.

Further observations are pending.

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


GRB_name: GRB220921A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32572
SUBJECT: GRB 220921A: MeerLICHT afterglow observations
DATE:    22/09/22 10:02:05 GMT
FROM:    Simon de Wet at UCT  <dwtsim002@myuct.ac.za>

S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) and D.A.H Buckley (SAAO)
report on behalf of the MeerLICHT consortium:

Following the detection of GRB 220921A by Fermi/LAT (Pillera et al., GCN
32568), the 0.6m wide-field MeerLICHT telescope, located at Sutherland,
South Africa, obtained a repeated series of 60s exposures of a field
encompassing the entire LAT error box in the q,u,g,r,i,z bands following
the sequence quqgqrqiqz. Observations started at 01:29:34 UT on September
22 and continued for approximately two hours.

We detect the previously reported afterglow to GRB 220921A at a position
consistent with the MASTER and Swift/XRT positions (Lipunov et al., GCN
32570; Kingler et al., GCN 32571) with the following AB magnitudes at a
mid-time of September 22 01:46:00 UT, 0.61 days after the LAT trigger time:

u = 19.28 +/- 0.14
g = 18.64 +/- 0.03
q = 18.47 +/- 0.02
r = 18.43 +/- 0.04
i = 18.25 +/- 0.05
z = 18.24 +/- 0.11

We note that the source is exhibiting fading behaviour with respect to the
previously reported MASTER brightness (Lipunov et al., GCN 32570).

MeerLICHT is built and run by a consortium consisting of Radboud
University, University of Cape Town, the South African Astronomical
Observatory, the University of Oxford, the University of Manchester and the
University of Amsterdam.


GRB_name: GRB220921A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32574
SUBJECT: GRB 220921A: Fermi GBM detection
DATE:    22/09/22 17:01:16 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico and INFN Bari)
reports on behalf of the Fermi GBM Team:


"At 11:05:59.071 UT on 21 September 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220921A (trigger 685451164/ 220921462), which was also
detected by Fermi-LAT (Pillera et al. 2022, GCN #32568).

The on-ground calculated location, using the GBM trigger data, is

RA = 66.85, DEC = -40.0

(J2000 degrees, equivalent to 04h 27m, -40d 00'),
with a statistical uncertainty of 1 degree (radius, 1-sigma containment,
statistical only; 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 Fermi GBM on-ground Localization is consistent
with the Fermi-LAT position.

The angle from the Fermi LAT boresight
at the GBM trigger time is 69 degrees.

The GBM light curve consists of multiple emission episodes
with a duration (T90) of about 210 s (50-300 keV).
The time-averaged spectrum from T0 to T0+40 s is
best fit by a Band function with Epeak = 142 +/- 4 keV,
alpha = -0.90 +/- 0.02, and beta = -2.09 +/- 0.02.

The event fluence (10-1000 keV) in this time interval is
(5.92 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+11 s in the 10-1000 keV band
is 36.2 +/- 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: GRB220921A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32575
SUBJECT: Konus-Wind detection of GRB 220921A
DATE:    22/09/22 18:47:23 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

The bright, long-duration GRB 220921A
(Fermi-LAT detection: Pillera et al., GCN Circ. 32568;
Fermi-GBM detection: Bissaldi, GCN Circ. 32574)
triggered Konus-Wind at T0=39961.714 s UT (11:06:01.714).

The burst light curve shows the bright multipeaked initial
emission episode which starts at ~T0-3.7 s and ends at ~T0+38 s, 
followed by a weaker episode at T0+220 s.
The total duration of ~231 s.
The emission is seen up to ~8 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220921_T39961/

As observed by Konus-Wind, the burst
had a fluence of 9.71(-2.95,+2.35)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+9.216 s,
of 1.44(-0.25,+0.26)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+257.536 s)
is best fit in the 20 keV - 8 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.88(-0.47,+0.67),
the high energy photon index beta = -2.07(-0.50,+0.15),
the peak energy Ep = 126(-36,+85) keV
(chi2 = 93/78 dof).

The spectrum near the maximum count rate
(measured from T0+6.656 to T0+11.776 s)
is best fit in the 20 keV - 8 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.89(-0.14,+0.20),
the high energy photon index beta = -2.26(-0.19,+0.14),
the peak energy Ep = 203(-35,+36) keV
(chi2 = 106/78 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB220921A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32576
SUBJECT: GRB 220921A: DDOTI Detection of the Afterglow 
DATE:    22/09/23 14:19:41 GMT
FROM:    Alan M Watson at UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Simone
Dichiara (PSU), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD),
William H. Lee (UNAM), OcÃ©lotl Lopez (UNAM), Margarita Pereyra (UNAM),
and Eleonora Troja (GSFC/UMD) report:

We observed the field of the Fermi/LAT GRB 220921A (Pillera et al., GCN
Circ. 32568) with the DDOTI wide-field imager at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro Martir
(http://ddoti.astroscu.unam.mx) from 2022-09-23 11:51 to 12:24 UTC
(48.75 to 49.30 hours after the trigger) obtaining 2040 seconds of
exposure.

At the position of the OT detected by MASTER-Net (Lipunov et al., GCN
Circ. 32570) we detect a source with w = 19.31 +/- 0.13. We calibrate
our photometry against the APASS catalog.

The afterglow has continued to fade from the observations reported by
Lipunov et al. (GCN Circ. 32570) and de Wet et al. (GCN Circ. 32572).

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
Martir.


GRB_name: GRB220921A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32577
SUBJECT: GRB 220921A: ALMA detection
DATE:    22/09/23 16:37:36 GMT
FROM:    Tanmoy Laskar at U of Bath  <tanmoylaskar@gmail.com>

T. Laskar (University of Utah), K. D. Alexander (University of Arizona), E.
Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong
(Northwestern University), R. Margutti (UC Berkeley), C. G. Mundell
(University of Bath), and P. Schady (University of Bath) report on behalf
of a larger collaboration:

"We observed GRB 220921A (Pillera et al., GCN 32568) with the Atacama Large
Millimeter/Submillimeter Array (ALMA) at 97.5 GHz beginning on 2021
September 23 08:04 UT (45 h after the burst). Preliminary analysis reveals
a mm source with flux density of ~ 0.7 mJy at position:

RA (J2000) = 04:25:53.42
Dec (J2000) = -40:24:20.25

with uncertainty ~ 0.01" in each coordinate, consistent with the X-ray
position (N. Klinger, GCN 32571) and optical position (Lipunov et al., GCN
32570). Further observations are planned.

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


GRB_name: GRB220924A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32579
SUBJECT: GRB 220924A: Fermi GBM Final Real-time Localization
DATE:    22/09/24 21:55:30 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 21:44:54 UT on 24 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220924A (trigger 685748699.41428 / 220924906).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 321.5, Dec = 33.8 (J2000 degrees, equivalent to J2000 21h 26m, 33d 47'), with a statistical uncertainty of 5.2 degrees.

The angle from the Fermi LAT boresight is 91.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220924906/quicklook/glg_skymap_all_bn220924906.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220924906/quicklook/glg_healpix_all_bn220924906.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220924906/quicklook/glg_lc_medres34_bn220924906.gif


GRB_name: GRB220925A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32581
SUBJECT: GRB 220925A: Fermi GBM Final Real-time Localization
DATE:    22/09/25 11:16:15 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 11:05:56 UT on 25 Sep 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220925A (trigger 685796761.09205 / 220925462).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 156.7, Dec = 45.0 (J2000 degrees, equivalent to J2000 10h 26m, 45d 00'), with a statistical uncertainty of 5.6 degrees.

The angle from the Fermi LAT boresight is 10.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220925462/quicklook/glg_skymap_all_bn220925462.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220925462/quicklook/glg_healpix_all_bn220925462.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220925462/quicklook/glg_lc_medres34_bn220925462.gif


GRB_name: GRB220921A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32582
SUBJECT: GRB 220921A: further MeerLICHT observations
DATE:    22/09/25 15:34:07 GMT
FROM:    Simon de Wet at UCT  <dwtsim002@myuct.ac.za>

S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) and D.A.H Buckley (SAAO)
report on behalf of the MeerLICHT consortium:

The 0.6m wide-field MeerLICHT telescope obtained a total of six 300s
exposures in the qugrizq bands in order to monitor the evolving afterglow
of GRB 220921A. Observations started at 00:34:09 UT on September 24,
approximately 2.56 days post-trigger. We detect the afterglow with a SNR >
5 in the qugri bands and with a SNR of 3.8 in the z band. We report the
following magnitudes:

u = 20.63 +/- 0.21
g = 20.52 +/- 0.10
q = 20.23 +/- 0.04
r = 20.16 +/- 0.10
i = 20.24 +/- 0.14
z = 19.91 +/- 0.28

We note that the source is continuing to fade.

MeerLICHT is built and run by a consortium consisting of Radboud
University, University of Cape Town, the South African Astronomical
Observatory, the University of Oxford, the University of Manchester and the
University of Amsterdam.


GRB_name: GRB220924A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32583
SUBJECT: GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
DATE:    22/09/25 22:33:21 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), James DeLaunay
(UAlabama), Jamie A. Kennea (PSU), report:

Swift/BAT did not localize GRB 220924A onboard (T0:
2022-09-24T21:44:54 UTC, Fermi/GBM GCN 32579).

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,
arXiv:2111.01769), detects the burst with a sqrt(TS) of 10.4 in a
16.384 s analysis time bin.

NITRATES results are consistent with a burst coming from outside the
FOV, with DeltaLLHOut of 2.

See Section 9.1 and Figure 20 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://www.swift.psu.edu/guano


GRB_name: GRB220925A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32584
SUBJECT: Fermi GRB 220925A: Global MASTER-Net observations report 
DATE:    22/09/26 08:30:12 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220925A ( Fermi GBM team, GCN 32581) errorbox  20648 sec after notice time and 20680 sec after trigger time at 2022-09-25 16:50:36 UT, with upper limit up to  18.4 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -37.4 deg. 

The galactic latitude b = 57 deg., longitude l = 172 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2100700

We obtain a following upper limits.  

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

   20711 | 2022-09-25 16:50:36 |         MASTER-Amur | (09h 55m 45.23s , +50d 35m 02.1s) |   C |    60 | 18.4 |        
   21002 | 2022-09-25 16:55:27 |         MASTER-Amur | (10h 08m 20.43s , +50d 35m 33.2s) |   C |    60 | 18.3 |        
   21083 | 2022-09-25 16:56:49 |         MASTER-Amur | (10h 21m 01.26s , +52d 29m 42.1s) |   C |    60 | 18.2 |        
   21163 | 2022-09-25 16:58:09 |         MASTER-Amur | (10h 34m 03.47s , +52d 28m 52.9s) |   C |    60 | 18.0 |        
   21243 | 2022-09-25 16:59:28 |         MASTER-Amur | (09h 56m 14.55s , +48d 42m 01.1s) |   C |    60 | 18.4 |        
   21323 | 2022-09-25 17:00:48 |         MASTER-Amur | (10h 08m 21.92s , +48d 40m 46.0s) |   C |    60 | 18.3 |        
   40602 | 2022-09-25 22:22:07 |             MASTER- | (10h 09m 59.28s , +50d 57m 20.4s) |   C |    60 | 14.1 |        
   40913 | 2022-09-25 22:27:18 |             MASTER- | (09h 57m 58.20s , +50d 50m 11.0s) |   C |    60 | 13.5 |        
   41785 | 2022-09-25 22:41:51 |             MASTER- | (10h 09m 54.42s , +50d 57m 30.4s) |   C |    60 | 16.9 |        
   41785 | 2022-09-25 22:41:51 |             MASTER- | (10h 21m 56.63s , +50d 49m 56.3s) |   C |    60 | 13.7 |        
   41935 | 2022-09-25 22:44:21 |             MASTER- | (09h 47m 25.27s , +47d 11m 46.8s) |   C |    60 | 16.9 |        
   41935 | 2022-09-25 22:44:21 |             MASTER- | (09h 58m 36.81s , +47d 04m 04.7s) |   C |    60 | 16.9 |        
   42013 | 2022-09-25 22:45:39 |             MASTER- | (09h 58m 04.54s , +48d 56m 45.7s) |   C |    60 | 16.7 |        
   42240 | 2022-09-25 22:49:26 |             MASTER- | (09h 49m 02.24s , +45d 17m 59.1s) |   C |    60 | 16.9 |        
   42240 | 2022-09-25 22:49:26 |             MASTER- | (09h 59m 51.22s , +45d 10m 11.4s) |   C |    60 | 15.8 |        
   42780 | 2022-09-25 22:58:26 |             MASTER- | (10h 10m 02.43s , +50d 58m 23.8s) |   C |    60 | 17.5 |        
   42780 | 2022-09-25 22:58:26 |             MASTER- | (10h 22m 06.91s , +50d 50m 47.7s) |   C |    60 | 14.6 |        
   42858 | 2022-09-25 22:59:43 |             MASTER- | (10h 09m 27.82s , +49d 03m 50.3s) |   C |    60 | 17.1 |        
   42858 | 2022-09-25 22:59:43 |             MASTER- | (10h 21m 04.00s , +48d 56m 10.7s) |   C |    60 | 13.4 |        
   42935 | 2022-09-25 23:01:01 |             MASTER- | (09h 47m 33.11s , +47d 10m 00.5s) |   C |    60 | 17.0 |        
   42935 | 2022-09-25 23:01:01 |             MASTER- | (09h 58m 44.35s , +47d 02m 21.2s) |   C |    60 | 17.6 |        
   43013 | 2022-09-25 23:02:19 |             MASTER- | (09h 58m 03.69s , +48d 57m 27.4s) |   C |    60 | 17.8 |        
   43091 | 2022-09-25 23:03:36 |             MASTER- | (10h 33m 57.47s , +50d 57m 53.6s) |   C |    60 | 17.0 |        
   43091 | 2022-09-25 23:03:36 |             MASTER- | (10h 46m 01.86s , +50d 50m 13.6s) |   C |    60 | 13.6 |        
   43168 | 2022-09-25 23:04:54 |             MASTER- | (09h 49m 09.28s , +45d 17m 32.7s) |   C |    60 | 17.2 |        
   43168 | 2022-09-25 23:04:54 |             MASTER- | (09h 59m 58.04s , +45d 09m 49.1s) |   C |    60 | 17.3 |        
   43323 | 2022-09-25 23:07:29 |             MASTER- | (10h 09m 40.66s , +47d 11m 59.5s) |   C |    60 | 17.0 |        
   43323 | 2022-09-25 23:07:29 |             MASTER- | (10h 20m 52.30s , +47d 04m 14.4s) |   C |    60 | 17.1 |        
   43556 | 2022-09-25 23:11:21 |             MASTER- | (10h 32m 37.50s , +49d 04m 23.6s) |   C |    60 | 17.0 |        
   43733 | 2022-09-25 23:14:19 |             MASTER- | (10h 10m 36.07s , +45d 16m 37.2s) |   C |    60 | 17.4 |        
   43733 | 2022-09-25 23:14:19 |             MASTER- | (10h 21m 24.40s , +45d 08m 46.9s) |   C |    60 | 16.2 |        
   43810 | 2022-09-25 23:15:36 |             MASTER- | (10h 09m 33.48s , +49d 05m 12.7s) |   C |    60 | 17.4 |        
   43810 | 2022-09-25 23:15:36 |             MASTER- | (10h 21m 09.99s , +48d 57m 35.5s) |   C |    60 | 17.5 |        
   43888 | 2022-09-25 23:16:54 |             MASTER- | (09h 47m 27.14s , +47d 10m 22.0s) |   C |    60 | 17.5 |        
   43888 | 2022-09-25 23:16:54 |             MASTER- | (09h 58m 38.30s , +47d 02m 45.0s) |   C |    60 | 12.8 |        
   44043 | 2022-09-25 23:19:29 |             MASTER- | (10h 34m 02.30s , +50d 58m 31.1s) |   C |    60 | 17.2 |        
   44043 | 2022-09-25 23:19:29 |             MASTER- | (10h 46m 06.72s , +50d 50m 55.1s) |   C |    60 | 14.7 |        
   44121 | 2022-09-25 23:20:46 |             MASTER- | (09h 49m 04.30s , +45d 15m 32.0s) |   C |    60 | 17.3 |        
   44121 | 2022-09-25 23:20:46 |             MASTER- | (09h 59m 52.45s , +45d 07m 53.1s) |   C |    60 | 17.1 |        
   44276 | 2022-09-25 23:23:21 |             MASTER- | (10h 09m 45.10s , +47d 11m 21.4s) |   C |    60 | 17.2 |        
   44276 | 2022-09-25 23:23:21 |             MASTER- | (10h 20m 56.41s , +47d 03m 42.4s) |   C |    60 | 17.4 |        
   44509 | 2022-09-25 23:27:14 |             MASTER- | (10h 32m 33.37s , +49d 04m 54.0s) |   C |    60 | 17.2 |        
   44509 | 2022-09-25 23:27:14 |             MASTER- | (10h 44m 09.80s , +48d 57m 14.2s) |   C |    60 | 15.7 |        
   44685 | 2022-09-25 23:30:11 |             MASTER- | (10h 10m 39.46s , +45d 17m 09.1s) |   C |    60 | 17.4 |        
   44685 | 2022-09-25 23:30:11 |             MASTER- | (10h 21m 27.82s , +45d 09m 24.0s) |   C |    60 | 16.9 |        
   44763 | 2022-09-25 23:31:28 |             MASTER- | (10h 12m 01.67s , +43d 22m 17.8s) |   C |    60 | 17.4 |        
   44763 | 2022-09-25 23:31:28 |             MASTER- | (10h 22m 29.51s , +43d 14m 29.3s) |   C |    60 | 15.9 |        
   44912 | 2022-09-25 23:33:58 |             MASTER- | (10h 31m 56.73s , +47d 12m 08.5s) |   C |    60 | 17.0 |        
   44912 | 2022-09-25 23:33:58 |             MASTER- | (10h 43m 07.17s , +47d 04m 31.1s) |   C |    60 | 17.4 |        
   44990 | 2022-09-25 23:35:16 |             MASTER- | (09h 51m 20.53s , +43d 22m 26.1s) |   C |    60 | 17.1 |        
   44990 | 2022-09-25 23:35:16 |             MASTER- | (10h 01m 47.49s , +43d 14m 52.0s) |   C |    60 | 17.8 |        
   45194 | 2022-09-25 23:38:39 |             MASTER- | (10h 06m 53.09s , +39d 27m 50.0s) |   C |    60 | 15.1 |        
   45271 | 2022-09-25 23:39:57 |             MASTER- | (10h 54m 17.06s , +47d 11m 29.1s) |   C |    60 | 17.0 |        
   45414 | 2022-09-25 23:42:20 |             MASTER- | (10h 14m 05.43s , +41d 30m 01.1s) |   C |    60 | 17.4 |        
   45695 | 2022-09-25 23:47:00 |             MASTER- | (10h 10m 36.16s , +45d 17m 37.4s) |   C |    60 | 17.7 |        
   45695 | 2022-09-25 23:47:00 |             MASTER- | (10h 21m 24.39s , +45d 10m 03.7s) |   C |    60 | 17.8 |        
   45773 | 2022-09-25 23:48:18 |             MASTER- | (10h 12m 08.78s , +43d 22m 46.5s) |   C |    60 | 17.5 |        
   45773 | 2022-09-25 23:48:18 |             MASTER- | (10h 22m 36.13s , +43d 15m 09.5s) |   C |    60 | 15.3 |        
   45850 | 2022-09-25 23:49:36 |             MASTER- | (10h 32m 05.63s , +45d 16m 06.5s) |   C |    60 | 17.5 |        
   45850 | 2022-09-25 23:49:36 |             MASTER- | (10h 42m 53.57s , +45d 08m 27.7s) |   C |    60 | 17.0 |        
   45928 | 2022-09-25 23:50:53 |             MASTER- | (10h 32m 04.39s , +47d 09m 51.8s) |   C |    60 | 17.3 |        
   45928 | 2022-09-25 23:50:53 |             MASTER- | (10h 43m 15.11s , +47d 02m 19.3s) |   C |    60 | 17.8 |        
   46005 | 2022-09-25 23:52:11 |             MASTER- | (09h 51m 18.24s , +43d 22m 45.2s) |   C |    60 | 17.4 |        
   46005 | 2022-09-25 23:52:11 |             MASTER- | (10h 01m 45.87s , +43d 15m 13.8s) |   C |    60 | 18.5 |        
   46083 | 2022-09-25 23:53:28 |             MASTER- | (09h 53m 57.62s , +41d 27m 45.3s) |   C |    60 | 17.5 |        
   46083 | 2022-09-25 23:53:28 |             MASTER- | (10h 04m 06.36s , +41d 20m 09.7s) |   C |    60 | 18.4 |        
   46160 | 2022-09-25 23:54:46 |             MASTER- | (10h 07m 00.44s , +39d 27m 09.7s) |   C |    60 | 18.3 |        
   46238 | 2022-09-25 23:56:04 |             MASTER- | (10h 54m 12.36s , +47d 11m 13.4s) |   C |    60 | 17.0 |        
   46238 | 2022-09-25 23:56:04 |             MASTER- | (11h 05m 23.23s , +47d 03m 35.0s) |   C |    60 | 17.0 |        
   46316 | 2022-09-25 23:57:21 |             MASTER- | (10h 55m 39.51s , +49d 05m 52.5s) |   C |    60 | 17.3 |        
   46393 | 2022-09-25 23:58:39 |             MASTER- | (10h 14m 13.32s , +41d 28m 44.0s) |   C |    60 | 17.2 |        
   46393 | 2022-09-25 23:58:39 |             MASTER- | (10h 24m 21.99s , +41d 21m 04.2s) |   C |    60 | 17.4 |        
   46703 | 2022-09-26 00:03:49 |             MASTER- | (10h 12m 07.78s , +43d 21m 42.6s) |   C |    60 | 17.3 |        
   46703 | 2022-09-26 00:03:49 |             MASTER- | (10h 22m 34.82s , +43d 14m 08.5s) |   C |    60 | 18.0 |        
   46781 | 2022-09-26 00:05:06 |             MASTER- | (10h 32m 12.10s , +45d 17m 34.4s) |   C |    60 | 16.8 |        
   46781 | 2022-09-26 00:05:06 |             MASTER- | (10h 43m 00.02s , +45d 09m 59.3s) |   C |    60 | 17.1 |        
   46858 | 2022-09-26 00:06:24 |             MASTER- | (10h 31m 58.55s , +47d 10m 40.9s) |   C |    60 | 16.6 |        
   46858 | 2022-09-26 00:06:24 |             MASTER- | (10h 43m 09.05s , +47d 03m 11.0s) |   C |    60 | 17.3 |        
   46936 | 2022-09-26 00:07:41 |             MASTER- | (09h 51m 15.90s , +43d 23m 04.3s) |   C |    60 | 16.8 |        
   46936 | 2022-09-26 00:07:41 |             MASTER- | (10h 01m 43.17s , +43d 15m 35.6s) |   C |    60 | 18.0 |        
   47013 | 2022-09-26 00:08:59 |             MASTER- | (09h 54m 00.42s , +41d 28m 08.6s) |   C |    60 | 17.1 |        
   47013 | 2022-09-26 00:08:59 |             MASTER- | (10h 04m 08.82s , +41d 20m 36.0s) |   C |    60 | 18.0 |        
   47091 | 2022-09-26 00:10:17 |             MASTER- | (10h 06m 56.48s , +39d 25m 33.2s) |   C |    60 | 17.8 |        
   47168 | 2022-09-26 00:11:34 |             MASTER- | (10h 54m 20.29s , +47d 10m 27.7s) |   C |    60 | 16.8 |        
   47168 | 2022-09-26 00:11:34 |             MASTER- | (11h 05m 30.80s , +47d 02m 52.6s) |   C |    60 | 17.5 |        
   47246 | 2022-09-26 00:12:51 |             MASTER- | (10h 55m 43.14s , +49d 05m 40.6s) |   C |    60 | 17.0 |        
   47323 | 2022-09-26 00:14:09 |             MASTER- | (10h 14m 10.29s , +41d 27m 36.7s) |   C |    60 | 16.9 |        
   47323 | 2022-09-26 00:14:09 |             MASTER- | (10h 24m 18.72s , +41d 20m 00.2s) |   C |    60 | 17.4 |        
   47556 | 2022-09-26 00:18:02 |             MASTER- | (10h 32m 52.55s , +43d 23m 56.6s) |   C |    60 | 17.4 |        
   47556 | 2022-09-26 00:18:02 |             MASTER- | (10h 43m 20.28s , +43d 16m 18.9s) |   C |    60 | 17.8 |        
   47699 | 2022-09-26 00:20:25 |             MASTER- | (10h 16m 41.29s , +39d 35m 34.9s) |   C |    60 | 17.1 |        
   47699 | 2022-09-26 00:20:25 |             MASTER- | (10h 26m 33.26s , +39d 27m 54.8s) |   C |    60 | 17.8 |        
   47777 | 2022-09-26 00:21:42 |             MASTER- | (10h 53m 40.90s , +45d 17m 13.2s) |   C |    60 | 17.3 |        
   47777 | 2022-09-26 00:21:42 |             MASTER- | (11h 04m 29.06s , +45d 09m 35.8s) |   C |    60 | 17.1 |        
   47981 | 2022-09-26 00:25:06 |             MASTER- | (10h 53m 42.42s , +43d 24m 19.9s) |   C |    60 | 17.1 |        
   47981 | 2022-09-26 00:25:06 |             MASTER- | (11h 04m 10.38s , +43d 16m 38.2s) |   C |    60 | 13.5 |        
   48058 | 2022-09-26 00:26:24 |             MASTER- | (10h 19m 54.68s , +37d 40m 32.0s) |   C |    60 | 16.7 |        
   48058 | 2022-09-26 00:26:24 |             MASTER- | (10h 29m 31.46s , +37d 32m 47.7s) |   C |    60 | 17.7 |        
   49574 | 2022-09-26 00:51:40 |             MASTER- | (10h 43m 21.81s , +43d 16m 32.3s) |   C |    60 | 17.4 |        
   49652 | 2022-09-26 00:52:57 |             MASTER- | (10h 34m 26.15s , +41d 29m 18.4s) |   C |    60 | 16.7 |        
   49652 | 2022-09-26 00:52:57 |             MASTER- | (10h 44m 35.04s , +41d 21m 26.4s) |   C |    60 | 17.1 |        
   49729 | 2022-09-26 00:54:15 |             MASTER- | (10h 16m 42.90s , +39d 33m 53.2s) |   C |    60 | 16.5 |        
   49729 | 2022-09-26 00:54:15 |             MASTER- | (10h 26m 34.48s , +39d 26m 03.4s) |   C |    60 | 17.6 |        
   49807 | 2022-09-26 00:55:33 |             MASTER- | (10h 53m 42.14s , +45d 16m 51.4s) |   C |    60 | 16.4 |        
   49807 | 2022-09-26 00:55:33 |             MASTER- | (11h 04m 30.15s , +45d 09m 03.4s) |   C |    60 | 17.6 |        
   49885 | 2022-09-26 00:56:50 |             MASTER- | (10h 36m 24.50s , +39d 36m 00.4s) |   C |    60 | 16.1 |        
   49885 | 2022-09-26 00:56:50 |             MASTER- | (10h 46m 16.28s , +39d 28m 08.5s) |   C |    60 | 17.6 |        
   49962 | 2022-09-26 00:58:08 |             MASTER- | (10h 53m 46.84s , +43d 22m 26.3s) |   C |    60 | 16.2 |        
   49962 | 2022-09-26 00:58:08 |             MASTER- | (11h 04m 13.93s , +43d 14m 37.4s) |   C |    60 | 17.5 |        
   50040 | 2022-09-26 00:59:25 |             MASTER- | (10h 19m 56.16s , +37d 41m 23.2s) |   C |    60 | 16.1 |        
   50040 | 2022-09-26 00:59:25 |             MASTER- | (10h 29m 32.30s , +37d 33m 34.3s) |   C |    60 | 16.8 |        
   50117 | 2022-09-26 01:00:43 |             MASTER- | (10h 54m 32.01s , +41d 29m 17.8s) |   C |    60 | 16.2 |        
   50574 | 2022-09-26 01:08:19 |             MASTER- | (10h 34m 21.04s , +41d 27m 52.3s) |   C |    60 | 16.8 |        
   50574 | 2022-09-26 01:08:19 |             MASTER- | (10h 44m 29.43s , +41d 20m 06.4s) |   C |    60 | 17.8 |        
   50651 | 2022-09-26 01:09:37 |             MASTER- | (10h 26m 40.09s , +39d 26m 00.2s) |   C |    60 | 17.5 |        
   50651 | 2022-09-26 01:09:37 |             MASTER- | (10h 16m 48.71s , +39d 33m 41.7s) |   C |    60 | 17.1 |        
   50728 | 2022-09-26 01:10:54 |             MASTER- | (10h 53m 39.97s , +45d 17m 36.6s) |   C |    60 | 17.1 |        
   50728 | 2022-09-26 01:10:54 |             MASTER- | (11h 04m 27.89s , +45d 09m 54.3s) |   C |    60 | 17.7 |        
   50806 | 2022-09-26 01:12:11 |             MASTER- | (10h 36m 25.02s , +39d 33m 52.3s) |   C |    60 | 17.2 |        
   50806 | 2022-09-26 01:12:11 |             MASTER- | (10h 46m 16.38s , +39d 26m 06.3s) |   C |    60 | 17.9 |        
   50883 | 2022-09-26 01:13:29 |             MASTER- | (10h 53m 49.92s , +43d 23m 54.7s) |   C |    60 | 17.2 |        
   50883 | 2022-09-26 01:13:29 |             MASTER- | (11h 04m 17.22s , +43d 16m 10.4s) |   C |    60 | 18.0 |        
   50961 | 2022-09-26 01:14:46 |             MASTER- | (10h 19m 50.03s , +37d 40m 29.5s) |   C |    60 | 17.2 |        
   50961 | 2022-09-26 01:14:46 |             MASTER- | (10h 29m 26.03s , +37d 32m 46.3s) |   C |    60 | 17.4 |        
   51038 | 2022-09-26 01:16:04 |             MASTER- | (10h 54m 31.68s , +41d 30m 04.8s) |   C |    60 | 17.0 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220926A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32585
SUBJECT: GRB 220926A: Swift detection of a burst
DATE:    22/09/26 10:04:24 GMT
FROM:    Kim Page at U.of Leicester  <kimlpage1978@gmail.com>

M. J. Moss (GWU), R. Brivio (INAF-OAB), S. Dichiara (PSU),
M. Ferro (INAF-OAB), N. P. M. Kuin (UCL-MSSL),
K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII),
T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) report on behalf
of the Neil Gehrels Swift Observatory Team:

At 09:22:50 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220926A (trigger=1125354).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 245.011, -16.043 which is 
   RA(J2000) = 16h 20m 03s
   Dec(J2000) = -16d 02' 32"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 40 sec.  The peak count rate
was ~400 counts/sec (15-350 keV), at ~5 sec after the trigger. 
The source is not well identified in the rate data which is typical 
of an image trigger. 

The XRT began observing the field at 09:25:04.4 UT, 134 seconds
after the BAT trigger. XRT found a bright, uncatalogued X-ray
source located at RA, Dec 245.0022, -16.0438 which is equivalent to:
   RA(J2000)  = 16h 20m 0.53s
   Dec(J2000) = -16d 02' 37.7"
with an uncertainty of up to 2 arcmin (radius, 90% containment). 
Given the star tracker loss of lock at the time of the trigger, it is 
unclear how accurate this localisation is, hence the large uncertainty 
listed.  No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 143 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image processing
FAILED because of no aspect solution. Results from the list of sources
generated on-board are not available at this time. No correction has been made
for the expected extinction corresponding to E(B-V) of 0.269. 

Note that this trigger occurred during an interval when the star
trackers had lost lock. However, we believe this to be a real GRB. 

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: GRB220926B
Detection_method: IBAS
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32586
SUBJECT: GRB 220926B
DATE:    22/09/26 11:24:44 GMT
FROM:    Diego Gotz at CEA  <diego.gotz@cea.fr>

D. Gotz (CEA Saclay), S.Mereghetti (INAF, IASF-Milano), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report:

a gamma-ray burst lasting about 20 s has been detected by IBAS in the IBIS/ISGRI data at 10:38:11 UT of 2022 September 26.

The refined coordinates (J2000) are:
R.A. =   273.9353 deg
DEC. =   -37.2414 deg
with an uncertainty of  1.0   arcmin (90% c.l.).


A plot of the light curve will  be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html


GRB_name: GRB220926B
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32587
SUBJECT: Analysis of long GRB 220926B detected by INTEGRAL
DATE:    22/09/26 15:46:31 GMT
FROM:    Sandro Mereghetti at IASF-Milano/INAF  <sandro.mereghetti@inaf.it>

S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno,
E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC,
Versoix) and J.Borkowski (CAMK, Torun) report:

GRB 220926B detected by IBAS in the IBIS/ISGRI (Gotz et al. GCN 32586) had
a peak flux > 2 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence
in the same energy range greater than 7e-7 erg/cmq (20 s integration time).
Due to telemetry saturation we can provide only lower limits to these
quantities.


GRB_name: GRB220926A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32588
SUBJECT: Swift GRB 220926A: Global MASTER-Net observations report 
DATE:    22/09/26 17:58:14 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220926A ( M. J. Moss et al., GCN 32585) errorbox  29605 sec after notice time and 29694 sec after trigger time at 2022-09-26 17:37:44 UT, with upper limit up to  18.3 mag. Observations started at twilight.  The observations began at zenith distance = 44 deg. The sun  altitude  is -13.6 deg. 

The galactic latitude b = 23 deg., longitude l = 359 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2101458

We obtain a following upper limits.  

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

   29785 |         MASTER-SAAO |   C |   180 | 18.0 |        
   29997 |         MASTER-SAAO |   C |   180 | 18.3 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220926A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32590
SUBJECT: Swift Trigger 1125354 (GRB 220926A) is not a GRB
DATE:    22/09/26 19:58:18 GMT
FROM:    Jamie Kennea at Penn State U  <jak51@psu.edu>

J. A. Kennea (PSU), K. J. Page (Leicester), S. Dichiara (PSU) and M. J. 
Moss (GWU) report on behalf of the Neil Gehrels Swift Observatory Team:

The Swift reported GRB 220926A (GCN #32585) is not a GRB. The trigger was 
caused by the combination of a star tracker outage and a trigger on Sco
X-1. Therefore we formally retract this GRB. We apologize for this error.


GRB_name: GRB220525B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32591
SUBJECT: Ultra-long GRB 220525B: Konus-Wind and Fermi-GBM detection
DATE:    22/09/26 21:01:55 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

and

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

The ultra-long GRB 220525B was initially found in
the Konus-Wind (KW) waiting mode data.

As observed by Konus-Wind the source of the burst
is in the southern ecliptic hemisphere
at ecliptic latitude of -32 +/- 22 deg (3 sigma).

A Bayesian block analysis of the KW waiting mode data in
the 20-1600 keV band reveals a 30 sigma count rate increase
over background in the interval from 13447 s UT (03:44:07),
hereafter T0, to 18763 s UT (05:12:43; T0 + 5316 s).
The burst lightcurve shows a single smooth pulse peaking at ~T0+600 s.

The Konus-Wind lightcurve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220525B/

As observed by Konus-Wind, the burst had a fluence of
1.94(-0.11,+0.13)x10^-4 erg/cm2 and a 2.944-s peak flux,
measured from ~T0+521 s, of 3.55(-0.77,+0.78)x10^-7 erg/cm2/s
(both in the 20 - 1500 keV energy band).

The KW 3-channel time-integrated spectrum
(from T0 to T0 + 3147 s)
can be described by a cutoff power-law model
with alpha = -0.24(-0.14,+0.15) and Ep = 478(-33,+48) keV.

All the quoted KW errors are estimated at the 1 sigma confidence level.

The Fermi-GBM Earth Occultation Technique was run over positions
covering the Konus-Wind ecliptic band, identifying a setting step of
a bright, uncatalogued source. The region that becomes occulted by Earth
for Fermi during the step time is weighted by the Konus-Wind ecliptic
band to generate the HEALPix map available at the Konus summary link.


GRB_name: GRB220924A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32593
SUBJECT: GRB 220924A: Fermi GBM detection
DATE:    22/09/27 01:12:16 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076@uah.edu>

S. Poolakkil (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 21:44:54.41 UT on 24 September 2022, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 220924A (trigger 685748699 / 220924906, GCN 32579)
which was also detected by the Swift/BAT- GUANO (Tohuvavohu et al. 2022,
GCN 32583).

The angle from the Fermi LAT boresight at the GBM trigger time is 91
degrees.

The GBM light curve consists of multiple peaks followed
by some extended emission with a duration (T90) of about 128 s (50-300 keV).
The time-averaged spectrum from T0-3.07 s to T0+131.07 s
is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.87 +/- 0.08  and
the cutoff energy, parameterized as Epeak, is 223 +/- 24 keV.

The event fluence (10-1000 keV) in this time interval is
(1.18 +/- 0.7)E-05  erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.86 s in the 10-1000 keV band
is 2.5 +/- 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: GRB220927A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32594
SUBJECT: GRB 220927A: Fermi GBM Final Localization
DATE:    22/09/27 14:39:49 GMT
FROM:    Joe Mangan at UCD  <joseph.mangan@ucdconnect.ie>

The Fermi GBM team reports the detection of a likely Long GRB.

"At 05:36:20.95 UT on 27 September 2022, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located GRB220927A (trigger 685949785 / 220927234).

The on-ground calculated location, using the GBM trigger data, is RA =
96.2, DEC = -22.5 (J2000 degrees, equivalent to 6h 24m, -22d 30'), with a
statistical uncertainty of 1 degrees (radius, 1-sigma containment,
statistical only; 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 at the GBM trigger time is 57
degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220927234/quicklook/glg_skymap_all_bn220927234.png

The HEALPix FITS file, including the estimated localization systematic, can
be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220927234/quicklook/glg_healpix_all_bn220927234.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220927234/quicklook/glg_lc_medres34_bn220927234.gif


GRB_name: GRB220611A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32595
SUBJECT: GRB 220611A: Host galaxy redshift from VLT/X-shooter
DATE:    22/09/27 15:22:02 GMT
FROM:    Benjamin Schneider at CEA  <benjamin.schneider@cea.fr>

B. Schneider (CEA Paris-Saclay), D. B. Malesani (Radboud Univ. and DAWN/NBI),
J. P. U. Fynbo (DAWN/NBI), K. Wiersema (Univ. Lancaster), L. Izzo (DARK/NBI),
A. J. Levan (Radboud Univ.) report on behalf of the Stargate collaboration:

We observed the location of GRB 220611A (Cenko et al., GCN 32191;
Goad et al., GCN 32192; Oâ€™Connor et al., GCN 32203; Rastinejad et al.,
GCN 32208; Malesani et al., GCN 32222; Levan et al., GCN 32262) using the
X-shooter spectrograph mounted on the ESO VLT UT3 (Melipal). Our target was
the faint object visible in the archival optical images from the Legacy Survey,
coincident with the optical and X-ray afterglow, first noticed by
Rastinejad et al. (GCN 32208).

The observation was performed on 2022 September 23 (104 days after the GRB)
and consisted of 4x1200 s in the UVB and VIS arms and 8x600 s in the NIR arm.
A filter was adopted to block part of the K band which in return increases
the efficiency of the J and H bands, resulting in a wavelength coverage
between 3000 to 21000 AA.

In a preliminary reduction, we detect several strong emission lines that
we identify as Lyman-alpha, [O II] 3729, [O III] 4959 and [O III] 5007 at a
common redshift of z = 2.3608 +/- 0.0002. The [O II] 3726 and H-beta lines
are affected by sky lines and are consequently not clearly detected. H-alpha
falls outside the covered wavelength range.

This result is supported by a VLT/MUSE spectrum obtained on 2022 August 24,
covering the wavelength range 4800 to 9300 AA, which shows no emission nor
absorption features, consistent with the measured redshift from X-shooter.

The positional coincidence between our target and the optical and X-ray
afterglow suggests a physical association. Furthermore, our spectra show
that the archival counterpart is a star-forming galaxy, akin to a typical
long GRB host. Our observations bring thus evidence that the GRB was not
physically associated with the local, nearby galaxy MCG-06-10-007 at z = 0.049
(Cenko et al., GCN 32191), and their proximity is a chance coincidence.

We acknowledge expert support from the ESO staff in Paranal, in particular
Thomas Rivinius and Michael Abdul-Masih.


GRB_name: GRB220921A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32596
SUBJECT: GRB 220921A: LCOGT Optical Observations
DATE:    22/09/27 18:10:04 GMT
FROM:    Robert Strausbaugh at University of Minnesota  <rstrausb@umn.edu>

R. Strausbaugh (University of Minnesota), A. Cucchiara (College of Marin)
report on behalf of a larger collaboration:

We observed the Fermi-LAT detection GRB 220921A (Pillera et al., GCN 32568)
field with the Las Cumbres Observatory Global Telescope Network (LCOGT)
1-meter Sinistro instrument at the South African Astronomical Observatory
site, on September 22, from 00:18 to 00:45 (corresponding to 13.22 to 14.57
hours from the GRB trigger time) with the Bessel I and R filters.

We performed a series of 3x300s exposures in R and I bands.  We detect the
MASTER optical afterglow candidate (Lipunov et al., GCN 32570), in both
bands, consistent with other optical detections (de Wet et al., GCN 32572;
Watson et al., GCN 32576).

The following magnitudes are calculated using the USNO-B1 catalog as
reference:

R= 18.02 +/- 0.27
I= 17.78 +/- 0.36

We also observed the afterglow of GRB 220921A with the LCOGT 1-meter
Sinistro instrument at the Cerro Tololo Interamerican Observatory, Chile
site, on September 23, from 04:50 to 05:18 (corresponding to 41.75 to 42.22
hours from the GRB trigger time) with the Bessel I and R filters.

We performed a series of 3x300s exposures in R and I bands.  We detect the
MASTER optical afterglow candidate (Lipunov et al., GCN 32570) in both
bands.

The following magnitudes are calculated using the USNO-B1 catalog as
reference:

R= 19.26 +/- 0.34
I= 19.03 +/- 0.39

These magnitudes are not corrected for galactic extinction.  Further
observations are planned.


GRB_name: GRB220927A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32597
SUBJECT: IPN triangulation of GRB 220927A (long)
DATE:    22/09/27 19:38:36 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,

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM 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 220927A
(Fermi-GBM detection: Fermi GBM Team, GCN 32594)
has been detected by Fermi (GBM trigger 685949785),
INTEGRAL (SPI-ACS), Konus-Wind, Mars-Odyssey (HEND),
and Swift (BAT), so far, at about 20180 s UT (05:36:20).
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:
   90.969 (06h 03m 52s) -22.946 (-22d 56' 45")
 Corners:
   88.336 (05h 53m 21s) -23.483 (-23d 28' 59")
   88.391 (05h 53m 34s) -23.818 (-23d 49' 04")
   93.560 (06h 14m 14s) -22.267 (-22d 16' 00")
   93.494 (06h 13m 59s) -21.929 (-21d 55' 45")
 ---------------------------------------------
The error box area is 1.68 sq. deg, and its maximum
dimension is 5.1 deg (the minimum one is 20 arcmin).
The Sun distance was 90 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of, the
Fermi-GBM final localization (GCN 32594).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220927_T20180/IPN

The time history and spectrum will be given in forthcoming GCN Circulars.


GRB_name: GRB220927A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32598
SUBJECT: Fermi GRB 220927A: Global MASTER-Net observations report 
DATE:    22/09/27 22:45:17 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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 220927A ( Fermi GBM team, GCN 32594) errorbox  43499 sec after notice time and 61090 sec after trigger time at 2022-09-27 22:34:31 UT, with upper limit up to  17.4 mag. The observations began at zenith distance = 74 deg. The sun  altitude  is -56.2 deg. 

The galactic latitude b = -17 deg., longitude l = 236 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2102352

We obtain a following upper limits.  

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

   61121 | 2022-09-27 22:34:31 |         MASTER-SAAO | (06h 17m 38.05s , -29d 19m 22.8s) |   C |    60 | 17.4 |        
   61203 | 2022-09-27 22:35:54 |         MASTER-SAAO | (06h 26m 53.28s , -29d 18m 55.6s) |   C |    60 | 17.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220927A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32600
SUBJECT: Konus-Wind detection of GRB 220927A
DATE:    22/09/29 20:38:34 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 220927A
(Fermi-GBM detection: Fermi GBM Team, GCN 32594;
IPN triangulation: Kozyrev et al., GCN 32597)
triggered Konus-Wind at T0=20180.364 s UT (05:36:20.364).

The burst light curve shows a multipeaked initial emission
episode which starts at ~T0-1.9 s and ends at ~T0+8.3 s,
followed by a weaker episode at ~T0+35 s.
The total burst duration is ~46.7 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/GRB220927_T20180/

As observed by Konus-Wind, the burst
had a fluence of 4.18(-1.08,+1.60)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+3.968 s,
of 9.37(-2.57,+2.78)x10^-7 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+41.216 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.37(-0.77,+2.06),
the high energy photon index beta = -2.60(-7.40,+0.35),
the peak energy Ep = 40(-22,+15) keV,
chi2 = 93/96 dof.

The spectrum near the maximum count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.97(-0.43,+0.61),
the high energy photon index beta = -3.04(-6.96,+0.44),
the peak energy Ep = 48(-6,+6) keV,
chi2 = 83/94 dof.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB220930A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32603
SUBJECT: GRB 220930A: Swift detection of a burst
DATE:    22/09/30 11:36:03 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

S. B. Cenko (GSFC), A. P. Beardmore (U Leicester), C. Gronwall (PSU),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester)
and T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil
Gehrels Swift Observatory Team:

At 11:11:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220930A (trigger=1125809).  Swift slewed immediately to the
burst.
The BAT on-board calculated location is
RA, Dec 64.737, +13.352 which is
   RA(J2000) = 04h 18m 57s
   Dec(J2000) = +13d 21' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 20 sec and a secondary peak at about
70 seconds after the trigger time.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.

The XRT began observing the field at 11:14:42.1 UT, 170.0 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 64.7149, 13.3500 which is equivalent to:
   RA(J2000)  = 04h 18m 51.58s
   Dec(J2000) = +13d 21' 00.0"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 77 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.

The initial flux in the 2.5 s image was 3.09e-09 erg cm^-2 s^-1 (0.2-10
keV).

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 179 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 100% of the XRT error circle. The typical 3-sigma upper
limit has been about 19.6 mag. 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 0.639.

Burst Advocate for this burst is S. B. Cenko (brad.cenko 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: GRB220930A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32604
SUBJECT: GRB 220930A: COATLI Upper Limits 
DATE:    22/09/30 12:09:45 GMT
FROM:    Alan M Watson at UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Simone Dichiara (PSU), Tzveti Dimitrova (ASU), OcÃ©lotl LÃ³pez (UNAM), Diego GonzÃ¡lez (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra (UNAM), Eleonora Troja (UTV/ASU) and report:

We observed the field of the Swift/BAT GRB 220930A (Cenko, GCN Circ. 32603) with the COATLI 50-cm telescope and HUITZI f/8 imager at the Observatorio AstronÃ³mico Nacional on the Sierra de San Pedro MÃ¡rtir (http://coatli.astroscu.unam.mx) from 2022-09-30 11:22 UTC to 11:59 UTC (10.5 to 48 minutes after the trigger), obtaining a total of 1920 seconds of exposure in the r filter.

We do not detect any uncataloged sources in the XRT error region (Cenko, GCN Circ. 32603) to a 3-sigma limit of r = 22.5.

Our photometry is calibrated against the Pan-STARRS1 catalog, are on an approximate AB system, and are not corrected for Galactic extinction in the direction of the GRB.

We thank the COATLI/HUITZI technical team and the staff of the Observatorio AstronÃ³mico Nacional.


GRB_name: GRB220930A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32605
SUBJECT: GRB 220930A: Prompt enhanced Swift-XRT position
DATE:    22/09/30 12:16:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using  promptly downlinked XRT event data for GRB 220930A, we find an
enhanced XRT position of the afterglow: RA, Dec: 64.71723, 13.34924
which is equivalent to:
   RA (J2000)  = 04 18 52.14
   Dec (J2000) = +13 20 57.3
with an uncertainty of 1.9 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/1125809.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB220930A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32606
SUBJECT: GRB 220930A: BOOTES-5/JGT early optical upper limit
DATE:    22/09/30 13:19:08 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report:

Following the detection of GRB 220930A by Swift (Cenko et al. GCNC 32603), the BOOTES-5/JGT 0.6m robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) observed the GRB location starting on Sep. 30, 11:13:05 UT (~ 73 s after trigger). In the early co-added image (18 x 10 s exposures in the clear filter), no optical afterglow is detected within the enhanced Swift/XRT error region (Evans et al. GCNC 32605) down to 21.0 mag, which is consistent with the limits reported by UVOT (Cenko et al. GCNC 32603) and COATLI (Watson et al. GCNC 32604).

We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support.


GRB_name: GRB220930A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32607
SUBJECT: Swift GRB 220930A: Global MASTER-Net observations report 
DATE:    22/09/30 15:08:15 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(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) was pointed to the Swift GRB 220930A ( S. B. Cenko et al., GCN 32603) errorbox  11539 sec after notice time and 11568 sec after trigger time at 2022-09-30 14:24:40 UT, with upper limit up to  19.3 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -41.3 deg. 

The galactic latitude b = -25 deg., longitude l = 181 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2105765

We obtain a following upper limits.  

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

   11659 |         MASTER-Amur |   C |   180 | 19.3 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB220930A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32608
SUBJECT: GRB 220930A: Enhanced Swift-XRT position
DATE:    22/09/30 15:35:59 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 892 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 220930A, 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 = 64.71717, +13.34902 which is equivalent
to:

RA (J2000): 04h 18m 52.12s
Dec (J2000): +13d 20' 56.5"

with an uncertainty of 2.2 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: GRB220930A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32609
SUBJECT: GRB 220930A: Swift/UVOT Upper Limits
DATE:    22/09/30 20:39:10 GMT
FROM:    Alexander Belles at PSU/Swift  <aub1461@psu.edu>

A. Belles (PSU) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220930A
180 s after the BAT trigger (Cenko et al., GCN Circ. 32603).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 32608)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

wh_FC              180          330          147            >20.71
u_FC               338          588          245            >19.95
wh                 618         1368          225            >20.93
v                  669         1418           97            >18.73
b                  594         1343           77            >19.59
u                  744         1318           58            >18.99
w1                 719         1467           77            >18.83
m2                 693         1442           77            >18.59
w2                 644         1393           97            >19.10


The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.639 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB220930A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32610
SUBJECT: GRB 220930A: LCOGT Optical Upper Limits
DATE:    22/10/01 04:03:35 GMT
FROM:    Robert Strausbaugh at University of Minnesota  <rstrausb@umn.edu>

R. Strausbaugh (University of Minnesota), A. Cucchiara (College of Marin)
report on behalf of a larger collaboration:

We observed the Swift GRB 220930A (Cenko et al., GCN 32603) field with the
LCOGT 1-meter Sinistro instrument at the South African Astronomical
Observatory site, on October 1, from 00:42 to 01:24 (corresponding to 13.52
to 14.22 hours from the GRB trigger time) with the SDSS i and r filters.

We performed a series of 3x300s exposures in i and r bands.  We do not
detect any uncatalogued sources in the XRT enhanced error region (Evans et
al., GCN 32608), in either band, consistent with other optical upper limits
(Watson et al., GCN 32604; Hu et al., GCN 32606; Belles et al., GCN 32609).

The following upper limits are calculated using the Pan-STARRS catalog as
reference:

r > 22.08
i > 21.73

These magnitudes are not corrected for galactic extinction.


GRB_name: GRB220930A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32611
SUBJECT: GRB 220930A: Swift-XRT refined Analysis
DATE:    22/10/01 04:58:30 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), D.N. Burrows
(PSU), J. D. Gropp (PSU), S. Dichiara (PSU), K.L. Page (U. Leicester),
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. D'Ai
(INAF-IASFPA) and S.B. Cenko report on behalf of the Swift-XRT team:

We have analysed 6.9 ks of XRT data for GRB 220930A (Cenko et al. GCN
Circ. 32603), from 160 s to 35.9 ks after the  BAT trigger. The data
comprise 390 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN Circ. 32605).

The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=1.28 (+/-0.11).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.59 (+/-0.08). The
best-fitting absorption column is  4.9 (+0.6, -0.5) x 10^21 cm^-2, in
excess of the Galactic value of 2.8 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.82 (+0.16, -0.15)
and a best-fitting absorption column of 6.4 (+1.2, -1.1) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.7 x 10^-11 (7.3 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      6.4 (+1.2, -1.1) x 10^21 cm^-2
Galactic foreground: 2.8 x 10^21 cm^-2
Excess significance: 5.4 sigma
Photon index:      1.82 (+0.16, -0.15)

If the light curve continues to decay with a power-law decay index of
1.28, the count rate at T+24 hours will be 0.017 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.3 x
10^-13 (1.3 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01125809.

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


GRB_name: GRB220930A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32612
SUBJECT: GRB 220930A: Swift-BAT refined analysis
DATE:    22/10/02 03:35:10 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha@nasa.gov>

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/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (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 220930A (trigger #1125809)
(Cenko et al., GCN Circ. 32603).  The BAT ground-calculated position is
RA, Dec = 64.725, 13.353 deg which is
   RA(J2000)  =  04h 18m 54.0s
   Dec(J2000) = +13d 21' 12.0"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.


The BAT light curve showed a complex structure with a duration of about 200 sec.
T90 (15-350 keV) is 180.47 +- 104.20 sec (estimated error including systematics).

The time-averaged spectrum from T-0.42 to T+235.67 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.59 +- 0.13.  The fluence in the 15-150 keV band is 5.5 +- 0.4 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-0.31 sec in the 15-150 keV band
is 6.2 +- 1.0 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1125809/BA/


GRB_name: GRB220930A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32613
SUBJECT: GRB 220930A: AstroSat CZTI detection
DATE:    22/10/02 05:27:01 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

R. Gopalakrishnan (IUCAA), V. Prasad (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 GRB 220930A which was 
also detected by Swift-BAT (Cenko et at., GCN 32603), Swift-XRT (Evans 
et al., GCN 32608), and Swift/UVOT (Belles et al., GCN 32609).

The source was clearly detected in the 20-200 keV energy range. The 
light curve peaks at 2022-09-30 11:11:52.50 UTC. The measured peak count 
rate associated with the burst is 435 (+49, -54) counts/s above the 
background in the combined data of all quadrants, with a total of 1508 
(+301, -353) counts. The local mean background count rate was 501 (+3, 
-3) counts/s. Using cumulative rates, we measure a T90 of 9 (+8, -5) s.

It was also clearly detected in the CsI anticoincidence (Veto) detector 
in the 100-500 keV energy range. The light curve peaks at 2022-09-30 
11:11:51.80 UTC. The measured peak count rate is 911 (+80, -88) counts/s 
above the background in the combined Veto data of all quadrants, with a 
total of 3694 (+515, -521) counts. The local mean background count rate 
was 1597 (+6, -7) counts/s. We measure a T90 of 13 (+5, -5) s from the 
cumulative Veto light curve.

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


GRB_name: GRB220930A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32614
SUBJECT: Konus-Wind detection of GRB 220930A
DATE:    22/10/02 17:09:27 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 220930A
(Swift-BAT detection: Cenko et al., GCN 32603,
Barthelmy et al., GCN 32612;
AstroSat-CZTI detection: Gopalakrishnan et al., GCN 32613)
triggered Konus-Wind at T0=40312.503 s UT (11:11:52.503).

The burst light curve shows a multipeaked structure
which starts at ~T0-1.5 s and has a total duration of ~76.0 s.
The emission is seen up to ~4 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220930_T40312/

As observed by Konus-Wind, the burst
had a fluence of 1.78(-0.64,+0.98)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.960 s,
of 5.39(-2.28,+2.15)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+73.984 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.06(-1.06,+1.43),
the high energy photon index beta = -2.41(-0.51,+0.46),
the peak energy Ep = 198(-58,+181) keV
(chi2 = 91/98 dof).

The spectrum near the maximum count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.38(-0.56,+0.66),
the high energy photon index beta = -2.25(-1.42,+0.23),
the peak energy Ep = 215(-52,+121) keV
(chi2 = 97/96 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB220930A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32617
SUBJECT: GRB 220930A: AbAO Optical Upper Limit
DATE:    22/10/02 22:48:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

N. Pankov (IKI), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI), S. Belkin 
(IKI, HSE), V. R. Ayvazian (AbAO),  D. Datashvili (AbAO), G. V. 
Kapanadze (AbAO) report on behalf of GRB IKI FuN:

We observed the field of GRB 220930A (Cenko et. al, GCN 32603) with 
AS-32 telescope of Abastumani Observatory (AbAO). We do not detect  any 
objects within enhanced Swift-XRT error region (Evans et. al, GCN 
32608). The 3-sigma upper limit is following:

   Date,     UT start, t-T0,    Exp.,  Filter, OT,    Err,  UL(3 sigma)
                      (mid, days)

2022-09-30 22:09:17  0.48085  70*60  R      n/d    n/d    22.3

The photometry is based on nearby USNO-B1.0 stars
USNO_B10_id  R2
1033-0057261 16.60
1033-0057239 17.39

The obtained result is consistent with non-detections reported earlier 
(Watson et. al, GCN 32604; Hu et al, GCN 32606; Lipunov et al, GCN 
32607; Belles and Cenko, GCN 32609; Strausbaugh and Cucchiara, GCN 32610).


GRB_name: GRB220921A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32618
SUBJECT: GRB 220921A: ATCA detection of radio counterpart
DATE:    22/10/03 06:49:53 GMT
FROM:    James Leung at U of Sydney/VAST  <jleu9465@uni.sydney.edu.au>

James Leung (University of Sydney/CSIRO), Ziteng Wang (University of
Sydney/CSIRO), Emil Lenc (CSIRO), Tara Murphy (University of Sydney)

The Australia Telescope Compact Array (ATCA) observed GRB 220921A
(Pillera et al., GCN 32568) at multiple frequencies starting on 2022
September 28, from 16:30 to 21:00 UTC (7.2 to 7.4d post-trigger).

We detect a radio source in all bands at the position:
RA (J2000) = 04:25:53.4
Dec (J2000) = -40:24:20.5

with uncertainty ~0.5" in each coordinate, which is consistent with 
the MASTER optical (Lipunov et al., GCN 32570) and ALMA mm (Laskar
et al., GCN 32577) candidate afterglow positions. 

We report our preliminary flux density measurements below:

Freq (GHz) | Peak Flux Density (micro-Jy/beam)
----------------------------------------------
5.5        | 163 +/- 19
9.0        | 364 +/- 17
16.7       | 763 +/- 50
21.2       | 988 +/- 95

Ongoing observations are planned. 

We thank CSIRO staff for rapidly scheduling and supporting these
observations.


GRB_name: GRB220927A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32622
SUBJECT: GRB220927A: Detection by GRBAlpha
DATE:    22/10/04 15:32:59 GMT
FROM:    Jakub Ripa at Masaryk University  <245487@mail.muni.cz>

A. Pal (Konkoly Observatory), J. Ripa, N. Werner (Masaryk U.), M. Ohno, 
H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), 
M. Dafcikova, N. Husarikova, J.-P. Breuer, F. Munz , M. Topinka, 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 220927A (Fermi-GBM detection: Fermi GBM Team, GCN 
32594; IPN triangulation: Kozyrev et al., GCN 32597; Konus-Wind 
detection: Ridnaia et al. GCN 32600) was detected by the GRBAlpha 1U 
CubeSat (Pal et al. Proc. SPIE 2020).

The 19.7 sigma detection was confirmed at the peak time 2022-09-27 
05:36:25.2 UTC. The GRB has the T90 duration of 8 s.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB220927A_GCN.pdf

GRBAlpha is a demonstration mission for a future CubeSats 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 about 50 keV to about 1000 keV. GRBAlpha was launched 
on 2021 March 22 from Baikonur. After its commissioning phase, the 
scientific observations are now under way. 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: GRB220912A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32624
SUBJECT: GRB 220912A: Detection by VZLUSAT-2
DATE:    22/10/05 07:21:28 GMT
FROM:    Jakub Ripa at Masaryk University  <245487@mail.muni.cz>

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, M. Dafcikova, 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.

A long-duration GRB 220912A (Fermi-GBM detection: Fermi GBM Team, GCN
32546; AstroSat CZTI detection: Gopalakrishnan et al. GCN 32549) was 
detected by a 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 
9.1 sigma detection was confirmed at 2022-09-12 00:50:23 UTC. The GRB 
has the T90 duration of 36 s.

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB220912A_GCN_VZLUSAT2.pdf

GRB detectors on VZLUSAT-2 are a demonstration payload for a future 
CubeSats 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: GRB220930A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32625
SUBJECT: GRB 2209030A: MITSuME Akeno optical upper limits
DATE:    22/10/05 08:46:19 GMT
FROM:    Tateda Mahiro at Tokyo Tech  <tateda@hp.phys.titech.ac.jp>

M. Tateda, I.Takahashi, K. L. Murata, Y. Imai, N. Ito, M. Niwano, S.
Sato, N. Higuchi, Y. Takamatsu, R. Hosokawa, M. Sasada, Y. Yatsu, and
N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:We
observed the field of GRB 220930A (S. B. Cenko et al. GCN Circular
#32603, Alan M. Watson et al. GCN Circular #32604, The Swift-XRT team
GCN Circular #32605,, Y.-D. Hu et al. GCN Circular #32606, V. Lipunov
et al. GCN Circular #32607, P.A. Evans et al. GCN Circular #32608, A.
Belles et al. GCN Circular #32609, R. Strausbaugh et al. GCN Circular
#32610, V. D'Elia et al. GCN Circular #32611, S. D. Barthelmy et al.
GCN Circular #32612, R. Gopalakrishnan et al. GCN Circular #32613,
A.Ridnaia et al. GCN Circular #32614, N. Pankov et al. GCN Circular
#32617) with the optical three color (g', Rc, and Ic) CCD cameras
attached to the MITSuME 50 cm telescope Akeno.The observation with a
series of 60 sec exposures started at 2022-09-30 13:10:00 UT (118.1
minutes after the Swift/BAT trigger). We stacked the images with good
conditions. We did not detect any uncatalogued sources within the
enhanced Swift/XRT error region (Evans et al. GCN Circular #32608). We
obtained the 5-sigma limits of the stacked images as follows.T0+[days]
| MID-UT | T-EXP[sec] | 5-sigma limits
------------------------------------------------------------------------------------------------
0.23 | 2022-09-30 16:39:02.52 | 14460 | g'>21.0, Rc>20.9, Ic>20.4
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure timeWe used PS1 catalog for flux calibration.
The magnitudes are expressed in the AB system. The images were
processed in real-time through the MITSuME GPU reduction pipeline
(Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24;
https://github.com/MNiwano/Eclaire)..


GRB_name: GRB221006A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32626
SUBJECT: GRB 221006A: MAXI/GSC detection
DATE:    22/10/06 02:15:28 GMT
FROM:    Motoko Serino at Aoyama Gakuin U.  <serino@phys.aoyama.ac.jp>

T. Mihara (RIKEN), M. Nakajima, H. Negoro (Nihon U.), W. Iwakiri (Chuo U.),
K. Kobayashi, M. Tanaka, Y. Soejima (Nihon U.),
T. Kawamuro, S. Yamada, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, M. Serino, S. Sugita, H. Hiramatsu, A. Yoshida (AGU),
Y. Tsuboi, J. Kohara (Chuo U.),
M. Shidatsu, M. Iwasaki (Ehime U.),
N. Kawai, M. Niwano, R. Hosokawa, Y. Imai, N. Ito, Y. Takamatsu (Tokyo Tech),
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, T. Kurihara (JAXA),
Y. Ueda, S. Ogawa, K. Setoguchi, T. Yoshitake, K. Inaba (Kyoto U.),
M. Yamauchi, T. Sato, R. Hatsuda, R. Fukuoka, Y. Hagiwara, Y. Umeki (Miyazaki U.),
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU),
M. Sugizaki (NAOC)  
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered on a bright uncatalogued X-ray 
transient source at 2022-10-06T00:57:09 UT.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (337.328 deg, 15.703 deg) = (22 29 18, +15 42 10) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.11 deg and 0.09 deg, respectively.
The roll angle of long axis from the north direction is 26.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 909 +- 81 mCrab
(4.0-10.0keV, 1 sigma error).

There was no significant excess flux in the previous transit at 10/5 23:24 UT
with an upper limit of 20 mCrab.


GRB_name: GRB221006A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32627
SUBJECT: GRB 221006A: Tiled Swift observations
DATE:    22/10/06 11:25:32 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 221006A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00108

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: 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: GRB221006A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32628
SUBJECT: GRB 221006A: Swift-XRT observations
DATE:    22/10/07 14:56:27 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

B. Sbarufatti (INAF-OAB), J. D. Gropp (PSU), S. Dichiara (PSU), J.A.
Kennea (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U.
Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 221006A (Mihara et al. GCN Circ. 32626) in a series of
observations tiled on the sky. The total exposure time is 1.9 ks,
distributed over 3 tiles; the maximum exposure at a single sky location
was 992 s. The data were collected between T0+37.6 ks and T0+39.8 ks,
and are entirely in Photon Counting (PC) mode. 

Three uncatalogued X-ray sources have been detected, however none of
them is above the RASS limit or shows definitive signs of fading.
Therefore, at the present time we cannot identify which, if any, is the
afterglow. Details of these sources are given below:

Source 1:
  RA (J2000):  337.3524  =  22:29:24.58
  Dec (J2000): +15.6341  =  +15:38:02.8
  Error: 12.1 arcsec (radius, 90% conf.)
  Count-rate: 0.0104 [+0.0063, -0.0045] ct s^-1   
  Distance: 262 arcsec from MAXI position.

Source 2:
  RA (J2000):  337.2458  =  22:28:58.99
  Dec (J2000): +15.7138  =  +15:42:49.6
  Error: 3.2 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0401 [+0.0076, -0.0070] ct s^-1   
  Distance: 287 arcsec from MAXI position.
  Flux: (1.67 [+0.32, -0.29])e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 3:
  RA (J2000):  337.3461  =  22:29:23.07
  Dec (J2000): +15.6941  =  +15:41:38.6
  Error: 8.2 arcsec (radius, 90% conf.)
  Count-rate: 0.0106 [+0.0043, -0.0034] ct s^-1   
  Distance: 70 arcsec from MAXI position.
  Flux: (2.00 [+0.81, -0.64])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00108.

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


GRB_name: GRB220915A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32629
SUBJECT: GRB 220915A: Detection by GRBAlpha
DATE:    22/10/07 19:56:55 GMT
FROM:    Jakub Ripa at Masaryk University  <245487@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. 
Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, 
B. Csak (Konkoly Observatory), N. Husarikova, J.-P. Breuer, F. Munz , M. 
Topinka, 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 220915A (Fermi-GBM detection trigger 684911625; 
Konus-Wind detection at 2022-09-15 05:13:46.2 UT; INTEGRAL/SPI-ACS 
detection at 2022-09-15 05:13:43 UT) was detected by the GRBAlpha 1U 
CubeSat (Pal et al. Proc. SPIE 2020).

The 8.4 sigma detection was confirmed at the peak time 2022-09-15 
05:13:42.9 UTC. The GRB has the T90 duration of 12 s.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB220915A_GCN.pdf

GRBAlpha is a demonstration mission for a future CubeSats 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. GRBAlpha was launched on 2021 
March 22 from Baikonur. After its commissioning phase, the scientific 
observations are now under way. 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: GRB221008A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32630
SUBJECT: GRB 221008A: MAXI/GSC detection
DATE:    22/10/08 02:00:23 GMT
FROM:    Hitoshi Negoro at Nihon U  <negoro.hitoshi@nihon-u.ac.jp>

Y. Soejima, H. Negoro, M. Nakajima (Nihon U.), M. Serino (AGU), 
W. Iwakiri (Chuo. U.), K. Kobayashi, M. Tanaka (Nihon U.), 
T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, M. Matsuoka (RIKEN), 
T. Sakamoto, S. Sugita, H. Hiramatsu, A. Yoshida (AGU), 
Y. Tsuboi, J. Kohara (Chuo U.),  M. Shidatsu, M. Iwasaki (Ehime U.),
N. Kawai, M. Niwano, R. Hosokawa, Y. Imai, N. Ito, Y. Takamatsu (Tokyo Tech), 
S. Nakahira,  S. Ueno, H. Tomida, M. Ishikawa,  T. Kurihara (JAXA), 
Y. Ueda, S. Ogawa, K. Setoguchi, T. Yoshitake, K. Inaba (Kyoto U.), 
M. Yamauchi, T. Sato, R. Hatsuda, R. Fukuoka, Y. Hagiwara, Y. Umeki (Miyazaki U.), 
K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 2022-10-08T00:53:50 UT.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (29.687 deg, -18.876 deg) = (01 58 44, -18 52 33) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.12 deg and 0.09 deg, respectively.
The roll angle of long axis from the north direction is 25.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
Without assumptions on the source constancy, we obtain a rectangular error
box for the transient source with the following corners:
(29.400, -18.665) deg = (01 57 35, -18 39 53) (J2000)
(29.338, -18.887) deg = (01 57 21, -18 53 13) (J2000)
(30.076, -19.070) deg = (02 00 18, -19 04 12) (J2000)
(30.137, -18.847) deg = (02 00 32, -18 50 49) (J2000)
The X-ray flux averaged over the scan was 803 +- 56 mCrab
(4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at 10/07 23:21 UT
 with an upper limit of 20 mCrab.


GRB_name: GRB221008A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32631
SUBJECT: GRB 221008A: Tiled Swift observations
DATE:    22/10/08 14:47:12 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 221008A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00109

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: 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: GRB221008A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32633
SUBJECT: GRB 221008A: Swift-XRT observations
DATE:    22/10/09 15:09:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A. D'Ai
(INAF-IASFPA), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 221008A (Soejima et al. GCN Circ. 32630) in a series of
observations tiled on the sky. The total exposure time is 1.2 ks,
distributed over 4 tiles; the maximum exposure at a single sky location
was 466 s. The data were collected between T0+50.0 ks and T0+51.4 ks,
and are entirely in Photon Counting (PC) mode. 

No uncatalogued X-ray sources have been detected. The 3-sigma upper
limit in the field (not including the regions where the tiles overlap)
ranges from ~0.03 to ~0.06 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 1.1e-12 to 2.4e-12 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

A previously-catalogued X-ray source has been detected, however because
it is a catalogued object it is unlikely to be the afterglow.

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00109.

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


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32635
SUBJECT: GRB 221009A: Swift detected transient may be GRB
DATE:    22/10/09 20:44:25 GMT
FROM:    Jamie Kennea at Penn State U  <jak51@psu.edu>

J. A. Kennea and M. Williams (PSU) report on behalf of the Swift Team:

We provide an update on the BAT trigger 1126853, AKA Swift J1913.1+1946   
(GCN #32632). Examination of XRT data from this trigger shows strong 
fading. We also note that Fermi/LAT has triggered on the same location.   
There is also a possible association with a Fermi/GBM trigger @ 
13:16:59UT. Given this, we believe that this source is now likely a 
Gamma-Ray Burst and not a Galactic Transient. If the GBM trigger is the   
same source, this would suggest a highly energetic outburst, and therefore
we strongly encourage follow-up of this usual event.


GRB_name: GRB221009A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32636
SUBJECT: GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
DATE:    22/10/09 20:54:36 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH),  E. Burns (LSU), E. Bissaldi (Politecnico and INFN
Bari), S. Lesage (UAH), O. Roberts (USRA)
report on behalf of the Fermi GBM Team:

"At 2022-10-09 13:16:59.000 UT on 9 October 2022, the Fermi Gamma-Ray
Burst Monitor (GBM) triggered and located GRB 221009A (trigger
687014224 / 221009553).

This event, if it is a GRB, it is the brightest among the GBM detected
GRBs. If it is not a GRB then it is a rare transient event. Follow-up
across all wavelengths is encouraged.

The on-ground calculated location, using the GBM trigger
data, is RA = 290.4, DEC = 22.3 (J2000 degrees,
equivalent to 19 h 22 m, 22 d 15 '), with a statistical uncertainty
of 1 degrees (radius, 1-sigma containment,
statistical only; 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] ).

This location is consistent with the Swift J1913.1+1946 localization
(Dichiara et al. GCN 32632)  though it precedes the Swift trigger by
an hour.


The angle from the Fermi LAT boresight at the GBM trigger time is 76 degrees.

The GBM light curve consists of an initial ~10 s long pulse, followed
by an extraordinarily bright episode at ~180 s after the trigger time,
lasting at least 100 seconds.



The 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: GRB221009A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32637
SUBJECT: GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
DATE:    22/10/09 21:45:05 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E Bissaldi (Politecnico and INFN Bari), N. Omodei (Stanford Univ.),
M. Kerr (NRL), report on behalf of the Fermi-LAT team:


At 14:17:05.99 on October, 09, 2022 Fermi-LAT detected high-energy emission
from Swift J1913.1+1946 or GRB 221009A, which was reported by
Swift (Dichiara et al. GCN #32632) and by GBM (Veres et al. GCN #32636).
The best LAT on-ground location is found to be

RA, Dec = 288.21, 19.73 (J2000)

with an error radius of 0.09 deg (90 % containment, statistical error only).
This was 94 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase in the event rate
that is spatially and temporally correlated with the trigger with high significance.

The 100 MeV - 1 GeV photon flux in the time interval 500-3500 s after
the Swift trigger is (1.27 +/- 0.16)E-05 ph/cm2/s.
The estimated photon index above 100 MeV is -2.12 +/- 0.11.
The highest-energy photon is a 7.8 GeV
which is observed 766 seconds after the Swift trigger.

The Fermi-LAT point of contact for this burst is
Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it).


The Fermi-LAT is a pair conversion telescope designed to
cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration
between NASA and DOE in the U.S. and many scientific
institutions across France, Italy, Japan and Sweden.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32638
SUBJECT: Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
DATE:    22/10/09 21:53:41 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley (LJMU) reports:

Imaging and spectroscopy were acquired of the optical counterpart of Swift J1913.1+1946 (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634), potentially the optical afterglow of GRB 221009A (Kennea & Williams, GCN 32635; Veres et al., GCN 32636).

The spectrum, taken with SPRAT between 20:49 and 21:06 UT on 2022-10-09, covers a wavelength range of 4000-8000 Angstroms and reveals a red continuum with no strong features.  Due to the low resolution of the spectrograph, we cannot rule out potential narrow absorption lines.  The shape is consistent with a heavily dust-reddened afterglow.  Galactic extinction towards this direction is about 3.52 mag in r-band (from the NED extinction calculator).

Imaging was acquired using IO:O in the SDSS g, r, i, and z filters between 21:18 and 21:23 UT on the same night.  We measure the following magnitudes, calibrating relative to local PS1 secondary standards:

MJD          filter mag    emag
59861.88806  g      18.53  0.06
59861.88896  r      17.00  0.03
59861.88982  i      15.98  0.03
59861.89069  z      15.32  0.03

Analysis is ongoing, and additional observations are planned.



DisclaimerNone


GRB_name: GRB221009A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32641
SUBJECT: IPN triangulation of extremely bright GRB 221009A
DATE:    22/10/10 01:10:40 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,

and

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

The extremely bright, long-duration GRB 221009A
(Swift-BAT detection of Swift J1913.1+1946:
Dichiara et al., GCN Circ. 32632; Kennea and Williams, GCN Circ. 32635;
Fermi-GBM detection: Veres et al., GCN Circ. 32636;
Fermi-LAT detection: Bissaldi et al., GCN Circ. 32636)
has been detected by Fermi (GBM trigger 687014224),
INTEGRAL (SPI-ACS), and Konus-Wind, so far,
at about 47820 s UT (13:17:00).

We have triangulated it to a Konus-GBN annulus centered at
RA(2000)=1.444 deg (00h 05m 47s) Dec(2000)=+3.590 deg (+3d 35' 25")
whose radius is 73.473 +/- 4.089 deg (3 sigma).

This localization may be improved.

The IPN localization is consistent with, but reduces the area of, the
Fermi-GBM one (glg_healpix_all_bn221009553_v01).

The IPN localization is consistent with Swift-BAT (GCN 32632) and
Fermi-LAT (GCN 32636) position of Swift J1913.1+1946, supporting that
Swift J1913.1+1946 is the afterglow of GRB 221009A.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB221009_T47819/IPN/

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


GRB_name: GRB221009A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32642
SUBJECT: GRB 221009A: Fermi GBM observation
DATE:    22/10/10 04:04:41 GMT
FROM:    Stephen Lesage at Fermi-GBM Team  <sjl0014@uah.edu>

S. Lesage (UAH), P. Veres (UAH), O.J. Roberts (USRA),
E. Burns (LSU), and E. Bissaldi (Politecnico and INFN Bari)
report on behalf of the Fermi GBM Team:

"At 13:16:59.99 UT on 09 October 2022, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 221009A (trigger 687014224/221009553) which
was also detected by Swift-BAT (S. Dichiara, et al. 2022, GCN 32632;
J. A. Kennea, et al. 2022, GCN 32635), Fermi-LAT (E. Bissaldi et al. 2022,
GCN 32637), INTEGRAL (SPI-ACS), Konus-Wind, and triangulated by IPN
(D. Svinkin et al. 2022, GCN 32641). The GBM on-ground location (GCN 32636)
is
consistent with the Swift-BAT and Fermi-LAT locations and the IPN
localization.

The angle from the Fermi LAT boresight is 73 degrees.

The GBM light curve consists of two emission episodes, a single isolated
peak
followed by a longer, extremely bright, multi-pulsed emission episode with
a duration (T90) of about 327 s (10-1000 keV).

The time-averaged spectrum for the first emission episode
from T0-0.0 to T0+43.4 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.70 +/- 0.02 and the cutoff energy,
parameterized as Epeak, is 375 +/- 87 keV.
The event fluence (10-1000 keV) in this time interval is
(2.12 +/- 0.05)E-05 erg/cm^2.

Due to the brightness of the second emission episode, the likelihood of
pulse pile-up and other systematic effects are very high and no single
spectral model provides an adequate fit in this preliminary analysis.
The event fluence (10-1000 keV) from T0+175 to T0+1458 s
is on the order of (2.912 +/- 0.001)E-02 erg/cm^2.
The 1.024 sec peak photon flux measured
starting from T0+238.8 s in the 10-1000 keV band
is on the order of 2385 +/- 3 ph/s/cm^2,
making this the most intense and fluent GRB detected by Fermi GBM.

Further analysis is being performed.

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: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32644
SUBJECT: GRB 221009A BOOTES-2/TELMA and OSN optical detections
DATE:    22/10/10 07:40:13 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

Y.-D. Hu, V. Casanova, E. Fernandez-Garcia, M. A. Castro Tirado, M.D. Caballero-Garcia, I. Olivares, I. Perez-Garcia and R. Sanchez-Ramirez and A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar and A. Castellon (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC) and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report:

The 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) responded to the extraordinarily bright GRB 221009A detected by Swift, Fermi, MAXI/GSC, INTEGRAL (SPI-ACS), Konus-Wind, and the IPN (Dichiara et al. GCNC 32632, Veres et al. GCNC 32636, Bissaldi et al. GCNC 32637, Svinkin et al. GCNC 32641, Negoro et al. ATEL 15651). A number of images (60s exposures in clear filter) were taken starting at 18:23 UT on 9 Oct (~ 4.2 hours after trigger). Due to passing clouds, the optical afterglow was only detected in frames around 18:44 UT with 16.21+/-0.11 mag.

Later on, we triggered the 0.9m telescope of the Observatiorio Sierra Nevada (OSN) near Granada, Spain. Observations started on 9 Oct 18:45 UT (~ 4.6 hours after trigger) in BVRI-bands (90 s exposures each). The optical afterglow is clearly detected with R=16.57+-0.02 mag on the first R-band image (gathered at 18:49 UT).

These detections are consistent with the ones reported by Lipunov et al. (GCNC 32634), Perley et al. (GCNC 32638) and Broens et al. (GCNC 32640). Further observations are ongoing.

We thank both the staff at La Mayora and OSN for their excellent support.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32645
SUBJECT: GRB 221009A (Swift J1913.1+1946): Mondy optical observations
DATE:    22/10/10 08:10:47 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed GRB 221009A (Swift J1913.1+1946) (Swift-BAT detection of 
Swift J1913.1+1946: Dichiara et al., GCN 32632; Kennea and Williams, GCN 
  32635; Fermi-GBM detection: Veres et al., GCN  32636; Fermi-LAT 
detection: Bissaldi et al., GCN  32636, IPN localization: Svinkin et 
al., GCN 32641) with AZT-33IK telescope of Sayan observatory (Mondy) 
starting on 2022-10-09 (UT) 14:26:54 and continuing to 15:34:05.

We clearly detect the optical afterglow (Dichiara et al., GCN 32632; 
Lipunov et al., GCN 32634; Perley GCN 32638; Hu et al., GCN 32644). 
Preliminary photometry of the afterglow at the first image is following

Date       UT start   t-T0       Filter Exp.   OT    Err.  UL(3sigma)
                     (mid, days)        (s)

2022-10-09 14:26:54  0.01223     R      120    14.84 0.09  20.8

We observe a monotonic decay in brightness, which can be approximated by 
a power law with an index of -0.52.

The photometry is based on the nearby USNO-B1.0 stars (R2)


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32646
SUBJECT: GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
DATE:    22/10/10 09:14:47 GMT
FROM:    Simon de Wet at UCT  <dwtsim002@myuct.ac.za>

S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) report on behalf of the
MeerLICHT consortium:

Following the detection by Swift of a bright hard new X-ray and optical
transient (Dichiara et al., GCN 32632), the 0.6m wide-field MeerLICHT
telescope, located at Sutherland, South Africa, started automatic
observations of the BAT error box beginning at 17:49:44 UT on 2022 October
9. Observations consisted of 60s exposures in the q,u,g,r,i,z bands
following the sequence quqgqrqiqz and continued for approximately 1 hour.
Some of our observations were affected by cirrus clouds.

We detect a source at the Swift/UVOT position (Dichiara et al., GCN 32632)
consistent with other optical detections (Lipunov et al., GCN 32634; Perley
et al., GCN 32638; Broens, GCN 32640), and report the following 3-sigma
u-band upper limit and detections in the AB magnitude system:

u > 17.91 at 18:06:27 UT
g = 18.22 +/- 0.33 at 18:21:07 UT
q = 17.19 +/- 0.07 at 18:05:00 UT
r = 17.76 +/- 0.08 at 18:23:59 UT
i = 15.58 +/- 0.03 at 18:26:56 UT
z = 14.89 +/- 0.03 at 18:29:55 UT

MeerLICHT is built and run by a consortium consisting of Radboud
University, University of Cape Town, the South African Astronomical
Observatory, the University of Oxford, the University of Manchester and the
University of Amsterdam.


GRB_name: GRB221009A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32647
SUBJECT: GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
DATE:    22/10/10 09:19:26 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

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

We observed the field of the optical counterpart of Swift J1913.1+1946 
or GRB 221009A detected by Swift (Dichiara, GCN 32632), using the 
NEXT-0.6m telescope located at Nanshan, Xinjiang, China. Observations 
started at 14:25:55 UT on 2022-10-09, i.e., 762 s after the Swift/BAT 
trigger. A series of frames in the Sloan r- and z- filters were obtained.

The optical counterpart is clearly detected in each of our images, which 
decays from r ~ 14.93 to r ~ 16.50 within ~ four hours, with a decay 
index of \alpha ~ 0.5 (F_t ~ t^-\alpha), calibrated the nearby PS1 
stars. The decaying behavior is consistent with that for conventional 
GRBs.

Spectroscopy of the optical counterpart was performed at the 2.16m 
telescope equipped with the BFOSC camera at Xinglong, Hebei, China. The 
spectrum covers the wavelength range 3800-9000 AA. The observation mid 
time is 2022 Oct 10.63 UT, i.e., 0.95 hr after the BAT trigger.

The spectrum is dominated by a red continuum due to very high Galactic 
extinction, and no prominent absorption feature can be identified. Given 
the detections by Swift/UVOT as well as spectral continuum, the event 
could be real GRB 221009A at a rather low redshift.

We thank the great support of the Xinglong-2.16m staff, in particular 
Junjun Jia, Min He, Aiying Zhou, and Jie Zheng.


GRB_name: GRB221009A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32648
SUBJECT: GRB 221009A: Redshift from X-shooter/VLT
DATE:    22/10/10 09:39:41 GMT
FROM:    Antonio de Ugarte Postigo at OCA  <deugarte@oca.eu>

A. de Ugarte Postigo (OCA), L. Izzo (DARK/NBI), G. Pugliese 
(Amsterdam Univ. and Leiden Observatory), D. Xu (NAOC), 
B. Schneider (CEA Paris-Saclay), J.P.U. Fynbo (DAWN/NBI), 
N.R. Tanvir (Univ. Leicester), D.B. Malesani (Radboud Univ. 
and DAWN/NBI), A. Saccardi (GEPI, Observatoire de Paris),  
D. A. Kann (Goethe Univ.), K. Wiersema (Lancaster Univ.), 
B. P. Gompertz (Birmingham), C. C. Thoene (ASU-CAS) and 
A. J. Levan (Radboud Univ.) report on behalf of the Stargate 
collaboration:

We observed the afterglow of the extremely bright GRB221009A 
(Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; 
Bissaldi et al., GCN 32637; Veres et al., GCN 32636; Lesage et 
al., GCN 32642) with X-shooter at ESO's UT3 of the Very Large 
Telescope (Paranal, Chile). The observations started at 
00:49:58.9 UT  (11.55 hr after the GBM trigger and 10.66 hr 
after the BAT trigger). The observation consisted of 4x600s with 
a spectral coverage between 3000 and 21000 AA.

We detect a very red continuum with absorption features that 
correspond to CaII, CaI and NaID at a redshift of z = 0.151. We 
also detect multiple features due to the Milky Wayâ€™s interstellar 
medium, due to the large Galactic column density of material 
along this line of sight. At this redshift the event has an isotropic 
equivalent energy of Eiso=2x10^54 erg (using the GBM fluence 
reported in GCN 32642), barring saturation effects in the 
Fermi/GBM fluence. This is within the upper end of GRB 
energetics. Further follow-up is strongly encouraged.

We acknowledge the excellent support provided by the Paranal 
staff, in particular A. Escorza and Zahed Wahhaj.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32650
SUBJECT: GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
DATE:    22/10/10 10:50:44 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

A. Ursi (INAF/IAPS), G. Panebianco (INAF/OAS-Bologna), C. Pittori, F.
Verrecchia (SSDC, and INAF/OAR), F. Longo (Univ. Trieste and INFN Trieste),
N. Parmiggiani (INAF/OAS-Bologna), M. Tavani (INAF/IAPS, and Univ. Roma Tor
Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano,
E. Menegoni, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A.
Addis, L. Baroncelli, A. Bulgarelli, A. Di Piano, V. Fioretti, F. Fuschino
(INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), and P.
Tempesta (TeleSpazio), report on behalf of the AGILE Team:

The AGILE satellite detected the bright emission classified as GRB 221009A
or Swift J1913.1+1946, reported by Swift BAT (GCN #32635) at T0 =
2022-10-09 13:16:59 (UTC), by Fermi GBM (GCNs # 32636, #31782), Fermi LAT
(GCN #32637), and IPN (GCN #32641).

The burst is clearly visible in the AGILE scientific ratemeters of the
MiniCALorimeter detector (MCAL; 0.4-100 MeV) and in all the five panels of
the AntiCoincidence system (AC Top, 50-200 keV; AC Lat, 80-200 keV). The
event consisted of several episodes, exhibiting an entire duration of about
600 s. The first episode lasted about 10 s and it released a total number
of 13870 counts in the MCAL detector (above a background rate of 1130 Hz),
and 31880 counts in the AC Top detector (above a background rate of 2980
Hz). The central episodes released a very large fluence, which produced
saturation effects in both MCAL and AC count rates, preventing a reliable
evaluation of the integrated counts. The last episode lasted 73 s and
released a total number of 517170 counts in the AC Top detector (above a
background rate of 2755 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/GRB221009A_AGILE_RM.png .

The event also triggered two partial high time resolution MCAL data
acquisitions, covering the onset of the central episodes. The
time-integrated spectrum of the first trigger, from T0+181.00 s to
T0+194.03 s, can be fitted in the energy range 0.5-5 MeV with a power-law
with ph.ind. = -2.07 (-0.04,+0.04), resulting in a reduced chi-squared of
1.98 (32 d.o.f.) and a fluence of 5.88e-04 erg/cm^2 (90% confidence level),
in the same energy range. Due to the extremely high fluence, the second
trigger is affected by pile-up and count rate saturation, preventing a
reliable evaluation of the corresponding energy spectrum. The MCAL light
curve can be found at
http://www.agilescienceapp.it/notices/GRB221009A_080412_592406219.000000.png
.

At the T0, the event was 100 deg off-axis.

Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert
Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.


GRB_name: GRB221009A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32651
SUBJECT: GRB 221009A: Swift-XRT refined Analysis
DATE:    22/10/10 11:19:36 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A.
Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB),
D.N. Burrows (PSU) and E Bissaldi report on behalf of the Swift-XRT
team:

We have analysed 12 ks of XRT data for GRB 221009A (E Bissaldi et al.
GCN Circ. 32637), from 159 s to 58.4 ks after the  BAT trigger. The
data are entirely in Windowed Timing (WT) mode (the first 10 s were
taken while Swift was slewing). A spectrum formed from the WT mode data
can be fitted with an absorbed power-law with a photon spectral index 
of 1.836 (+0.012, -0.011). The best-fitting absorption column is  6.76
(+/-0.16) x 10^21 cm^-2, at a redshift of 0.151, in addition to the
Galactic value of 5.4 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 5.7 x 10^-11 (1.0 x 10^-10) erg cm^-2
count^-1. 

A summary of the WT-mode spectrum is thus:
Galactic foreground: 5.4 x 10^21 cm^-2
Intrinsic column:    6.76 (+/-0.16) x 10^21 cm^-2 at z=0.151
Photon index:      1.836 (+0.012, -0.011)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01126853.

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


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32652
SUBJECT: GRB 221009A: REM optical and NIR detection of the afterglow
DATE:    22/10/10 11:22:17 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

R. Brivio, M. Ferro, P. D'Avanzo, D. Fugazza (INAF-OAB), A. Melandri (INAF-OAR), S. Covino (INAF-OAB) 
on behalf of the REM team, report:

We observed the field of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., 
GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) with the REM 
60cm robotic telescope  located at the ESO premise of La Silla (Chile). The observations were carried in the 
g, r, i, z, J, H and K bands, starting on 2022 Oct 09 at 23:43:02 UT (i.e. about 10.43 hours after the GBM trigger) 
and lasted for about 1 hour.

The optical and NIR afterglow is detected in all bands. From preliminary photometry, we derive the following magnitudes:

r = 17.36 +/- 0.12
(AB; calibrated against the the Pan-STARRS catalogue)

H = 12.21 +/- 0.04
(Vega; calibrated against the 2MASS catalogue) 


at a mid time of t-t0 ~ 10.47 hours after the GBM trigger.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32653
SUBJECT: GRB 221009A/Swift J1913.1+1946: AMI-LA observations
DATE:    22/10/10 12:10:49 GMT
FROM:    Lauren Rhodes at Oxford  <lauren.rhodes@physics.ox.ac.uk>

Joe Bright, Lauren Rhodes, Rob Fender (University of Oxford), Wael Farah, Alex Pollak, Andrew Siemion (SETI Institute) report:



We observed the field of the candidate gamma-ray burst GRB 221009A (Swift J1913.1+1946; ATel #15650, ATel #15651) with the Arcminute Microkelvin Imager Large-Array (AMI-LA) at 15.5 GHz beginning at UT 16:25:25.5 on 09-Oct-2022 (approximately 2 hours 15 minutes after the initial BAT trigger reported in ATel #15650) for a total of 4 hours. The flux standard 3c286 was used to calibrate the bandpass response and flux scale of the AMI-LA and J1925+2106 was used as an interleaved complex gain calibrator.

We detect a bright unresolved source at a position consistent with the one reported in ATel #15651 at a (preliminary) flux density of 39 +/- 2 mJy (including both a statistical uncertainty and a 5% absolute flux scale uncertainty). There is no significant emission at this position in either the VLA Sky Survey (VLASS; Lacy+2020) or the NRAO VLA Sky Survey (NVSS; Condon+1998), and so we identify this new source as the radio counterpart to GRB221009A/Swift J1913.1+1946. Further observations are planned.

We thank the staff at the Mullard Radio Astronomy Observatory for carrying out these observations and operating the AMI-LA.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32654
SUBJECT: GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
DATE:    22/10/10 12:15:59 GMT
FROM:    Igor Andreoni at JSI  <igor.andreoni@gmail.com>

J. M. Durbak (UMD), A. S. Kutyrev (NASA/GSFC), I. Andreoni (JSI), K. De
(MIT), E. Troja (U Tor Vergata/ASU), S. B. Cenko (NASA/GSFC), R. Hamada
(Osaka U), Y. Hirao (Osaka U), R. Kirikawa (Osaka U), I. Kondo (Osaka U),
S. Miyazaki (ISAS/JAXA), G. Mosby (NASA/GSFC), T. Sumi (Osaka U), D. Suzuki
(Osaka U), H. Yama (Osaka U)

We observed the field of the transient Swift J1913.1+1946 or GRB 221009A
(Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al.,
GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et
al., GCN Circ. 32650) with the PRIME near-infrared camera mounted on the
1.8m Telescope at SAAO.

Observations were carried out on 2022-10-09 around 18:50 UT, i.e. about 4.7
hours from the Swift/BAT detection (Dichiara et al., GCN 32632), 5.5 hours
after the Fermi/GBM detection (Veres et al., GCN 32636), and 1 day after
the PRIME instrument first light.

We detected a near-infrared source spatially consistent with the bright
optical transient previously reported, with preliminary photometry H~12.2
mag, calibrated against nearby 2MASS sources. Our result is consistent with
the REM detection (Brivio et al. GCN 32652) and suggests no significant
fading between 5.5 hr and 10.5 hr after the GBM trigger.

Archival deep near-infrared images of the field taken with WFCAM during the
UKIRT Galactic plane survey (Lawrence et al., 2007) do not show any
persistent source in J and H bands at the transient location.


These results are based on data obtained from PRIME at the South African
Astronomical Observatory (SAAO), Sutherland, South Africa.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32655
SUBJECT: GRB221009A/Swift J1913.1+1946: ATA follow-up observations
DATE:    22/10/10 12:32:57 GMT
FROM:    Lauren Rhodes at Oxford  <lauren.rhodes@physics.ox.ac.uk>

Wael Farah (SETI Institute), Joe Bright (University of Oxford), Alex Pollak, Andrew Siemion (SETI Institute), David DeBoer (UC Berkeley), Rob Fender, Lauren Rhodes, Ian Heywood (University of Oxford) report:

After the detection of a bright radio counterpart to GRB221009A at 15.5 GHz was reported in ATel #15653 /GCN #32653, we conducted follow-up observations with the Allen Telescope Array (ATA) at 1.5, 3, 4, 6, 8, and 10 GHz. Observations were carried out simultaneously at 1.5 + 3, 4 + 6 and 8 + 10 GHz, with a 672 MHz bandwidth centered on each frequency, using a newly deployed wideband correlator (Farah et al., in prep.), at spectral and temporal resolution of 0.5MHz and 10s, respectively. The target field was observed for 1 hour per pair of frequencies. The primary flux standard 3c286 was used to calibrate the absolute flux scale and bandpass response of the array, and J1925+2106 was used to calibrate the time dependent complex gains. Data flagging was performed with AOFlagger (Offringa+2012) while calibration and imaging were performed using standard techniques in CASA (McMullin+2007).

We clearly detect an unresolved radio source at a position consistent with the one reported in ATel #15650 at 1.5, 3, 6, 8, and 10 GHz. Preliminary flux densities at 3, 6, 8, and 10 GHz are reported below, and include a 10% absolute flux scale uncertainty in addition to the statistical error from the fit. Observations conducted at 4 GHz were severely corrupted by radio frequency interference and were not processed. Our observations indicate that the radio counterpart to GRB221009A/Swift J1913.1+1946 is self-absorbed below around 10 GHz, although there is apparently significant flux density evolution between observing epochs.


MJD                     Frequency (GHz)     Flux density (mJy)
59862.0492         3.0                           3.6 +/- 0.7
59861.9414         6.0                           9.0 +/- 1
59862.1242         8.0                           28  +/- 3
59862.1242         10.0                         38  +/- 4


The Allen Telescope Array is a 42-element radio interferometer located at the Hat Creek Radio Observatory in Northern California. The facility is fully operated by the SETI Institute.


GRB_name: GRB221009A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32656
SUBJECT: GRB 221009: Swift/UVOT Detection
DATE:    22/10/10 12:41:35 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and S. Dichiara (PSU) report on behalf

of the Swift/UVOT team:


The Swift/UVOT began settled observations of the field of

GRB 221009 179 s after the BAT trigger (Dichiara et al.,

GCN Circ. 32632, and 32633).  This GRB was initially reported as being

a new bright hard X-ray transient and named SwiftJ1913.1+1946.

Further analysis shows this is a GRB (Kennea et al, GCN Circ.

32635, and 32651).

The  preliminary UVOT position was reported in the Dichiara et al. GCN.

The GRB was also detected by Fermi (Veres et al. GCN Circ 32636;

Bissaldi et al. GCN Circ. 32637; Lesage etal. GCN Circ. 32642),

IPN (Svinkin et al.,  GCN Circ. 32641); Agile (Ursi et al. GCN

Circ 32650). A redshift of 0.151 has been reported by de Ugarte

Postigo et al. (GCN Circ. 32648), and optical detections were

reported also (MASTER: Lipunov et al., GCN Circ. 32634 and 32639;

Liverpool Telescope photometry and spectrum: Perley GCN Circ

32638;  VVS: Broens, GCN Circ. 32640; BOOTES-2/TELMA: Hu et al., GCN

Circ. 32644; Mondy: Belkin et al. GCN Circ. 32645; MeerLICHT: de Wet et al.

GCN Circ. 32646; Nanshan/NEXT photometry and Xinglong-2.16m

spectroscopy Xu et al. GCN Circ. 32647; Al Khatim Observatory:

Odeh, GCN Circ. 32649; REM: Brivio et al. GCN Circ. 32652). Near IR

was reported for PRIME by Durbak et al. GCN Circ. 32654 and radio

AMI-LA: Bright et al. GCN Circ. 32653 and ATA:Farah et al.  GCN Circ. 32655.

Pre-discovery limits from ZTF: Karambelkar et al. GCN Circ. 32643.


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              179          329          147         16.68 +/- 0.03
v                  668          688           20         15.55 +/- 0.10
b                  593          613           20         17.05 +/- 0.11
u                  337          587          246         17.68 +/- 0.06
w1                 718         1293           58        >18.2
w2                 817         1219           39        >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.563 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32657
SUBJECT: GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
DATE:    22/10/10 12:49:03 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

G. Piano (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli
(INAF/OAS-Bologna), A. Ursi (INAF/IAPS), G. Panebianco (INAF/OAS-Bologna),
C. Pittori, (SSDC, and INAF/OAR), F. Longo (Univ. Trieste and INFN
Trieste), N. Parmiggiani (INAF/OAS-Bologna), M. Tavani (INAF/IAPS, and
Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y.
Evangelista, L. Foffano, E. Menegoni, (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Addis, L. Baroncelli, A. Di Piano, V. Fioretti, F. Fuschino
(INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), and P.
Tempesta (TeleSpazio), report on behalf of the AGILE Team:

The GRID detector onboard the AGILE satellite detected the bright emission
classified as GRB 221009A or Swift J1913.1+1946, reported by Swift BAT (GCN
#32635) at T0 = 2022-10-09 13:16:59 (UTC), by Fermi GBM (GCNs # 32636,
#31782), Fermi LAT (GCN #32637), IPN (GCN #32641), AGILE/MCAL (GCN #32650),
Swift XRT (GCN #32651), and Swift UVOT (GCN #32656).

Integrating from 2022-10-09 UT 13:16:59 (T0) to 2022-10-09 UT 14:16:59 (T0
+ 1h), a preliminary multi-source likelihood analysis yields a detection
with a significance of 42 sigma and a gamma-ray flux F(>100 MeV) = (1.11
+/- 0.08) x 10^-3 photons/cm^2/s, by adopting a power-law model with a
(reference) photon index value of -2.1.

The angular position of the gamma-ray event, as detected by the AGILE/GRID,
is:

(l, b) =  (52.99, 4.26) +/- 0.17 deg (stat.) +/- 0.10 deg (syst.)

These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.


GRB_name: GRB221009A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32658
SUBJECT: GRB 221009A: Fermi-LAT refined analysis
DATE:    22/10/10 13:42:46 GMT
FROM:    Roberta Pillera at Politecnico and INFN Bari  <roberta.pillera@ba.infn.it>

GRB 221009A: Fermi-LAT refined analysis

R. Pillera (Politecnico and INFN Bari), E Bissaldi (Politecnico and INFN 
Bari),
N. Omodei (Stanford Univ.), G. La Mura (LIP, Portugal),
F. Longo (University and INFN Trieste) report on behalf of the Fermi-LAT 
team:


We report updated observations of GRB 221009A which was detected by
Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636,
Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637),
and the IPN (Svinkin et al. GCN #32641).

GRB 221009A triggered Fermi-GBM on October 10, 2022, at 13:16:59.99 UT
(trigger 687014224/221009553), about 1 hour earlier with respect
to the Swift trigger,  which was reported as a new bright
hard X-ray and optical transient and tentatively classified
as Swift J1913.1+1946 (Dichiara et al., GCN 32632).
Prompt GCN notices from Fermi-GBM were not distributed
due to problems with the real-time downlink from TDRS,
therefore no automatic Fermi-LAT GRB pipelines were triggered
by the GBM event.

Using LAT events with E>100 MeV between T0+200 s and T0+800 s,
we find a LAT localization of

RA = 288.282, Dec = 19.495,

with a 90% containment radius of 0.027 degrees (statistical only).

The LAT lightcurve shows a bright structured emission episode
which is temporally coincident with the GBM main emission episode
starting at T0+200s.
The 100 MeV - 1 GeV photon flux in the time interval 200-800 s after
the GBM trigger is (6.2 +/- 0.4)E-03 ph/cm2/s.
The estimated photon index above 100 MeV is -1.87 +/- 0.04.

 From a preliminary analysis, the LAT emission
is extending for about 25ks post GBM trigger.
The highest-energy photon is 99.3 GeV (with a probability of 99.2%)
which is observed 240 seconds after the GBM trigger.
This represents the highest GRB photon energy
ever detected by Fermi-LAT (the previous record holder being
a 95 GeV event from GRB 130427A).

The Fermi-LAT point of contact for this burst is
Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it).

The Fermi-LAT is a pair conversion telescope designed to
cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration
between NASA and DOE in the U.S. and many scientific
institutions across France, Italy, Japan and Sweden.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32659
SUBJECT: â€‹GRB 221009A: Multi-color detection of the optical
DATE:    22/10/10 14:16:00 GMT
FROM:    Gregory SungHak Paek at SNU  <shpaek@astro.snu.ac.kr>

Gregory S.H. Paek (SNU ARC/SNU), Myungshin Im (SNU ARC/SNU), Yuji Urata
(NCU), Hyun-Il Sung (KASI) on behalf of a larger collaboration

 We detected the optical counterpart/NIR afterglow of extremely bright GRB
221009A (Dichiara et al., GCN #32632) with the 1-m class telescopes in
Lemonsan Optical Astronomy Observatory (LOAO) facilities of the GW
EM-Counterpart Korean Observatory (GECKO).

 We observed the center of UVOT localization (RA, Dec = 288.265, +19.774)
+15 hours after the report in B, V, R, I, z, and Y-bands. We clearly
detected the afterglow in all V, R, I, z, and Y-bands except for the
B-band. We calibrated flux with the PANSTARRS catalog and used an AB
magnitude system. Depth means 5 sigma upper limit for a point source
detection. The magnitudes are not corrected for galactic extinction.

------------------- ----------- ----------- ------ ----------- ----------
----- ------ -----
DATE-OBS[UTC]       JD          t-t0[days]  FILTER Observatory EXPTIME[s]
MAG   MAGERR DEPTH
------------------- ----------- ----------- ------ ----------- ----------
----- ------ -----
2022-10-10T04:18:54 2459862.680 0.626       B      LOAO        60s*5
 None   None  19.66
2022-10-10T04:20:38 2459862.681 0.628       V      LOAO        60s*5
 18.74  0.13  19.48
2022-10-10T04:22:04 2459862.682 0.629       R      LOAO        60s*5
 17.55  0.06  19.75
2022-10-10T04:23:31 2459862.683 0.630       I      LOAO        60s*5
 16.41  0.05  19.56
2022-10-10T04:24:39 2459862.684 0.631       z      LOAO        60s*5
 TBD    TBD   TBD
2022-10-10T04:25:58 2459862.685 0.631       Y      LOAO        60s*5
 TBD    TBD   TBD

 We will continue the follow-up observation for this target with the LOAO,
and other GECKO facilities in Australia, and Chile. Gravitational-wave EM
Counterpart Korean Observatory (GECKO) is a network of 10+ 0.5m to 1m class
telescopes worldwide.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32661
SUBJECT: GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
DATE:    22/10/10 15:23:32 GMT
FROM:    Hualin Xiao at FHNW  <hualin.xiao@fhnw.ch>

Hualin Xiao, Sm Krucker and Ryan Daniel on behalf of the STIX team report:


At 2020-10-09T13:16:56 UT (Solar Orbiter onboard time), STIX detected GRB221009A, when STIX was 1.22 AU from the earth.


The gamma-ray burst is clearly visible in the STIX quick-look light curves of five energy bands in the range between 4 -150 keV.



The initial pulse lasted about 10 seconds, followed by two bright pulses, lasting about 80 seconds.

The fourth pulse was detected at ~ 323 s after the initial pulse.

STIX recorded 185000 triggers from the burst in total.



STIX light curves can be found at: https://datacenter.stix.i4ds.net/pub/GRB/GRB221009A/stix_GRB221009A_light_curves.png

and  https://datacenter.stix.i4ds.net/view/ql/lightcurves


Solar Orbiter location during the GRB: https://datacenter.stix.i4ds.net/pub/GRB/GRB221009A/GRB221009A_solar_orbiter_orbit.png



The analysis results presented above are preliminary.  The science data will only be down-linked from the instrument in a month or two.  Detailed analysis of the event will be started after downloading the science data.


The Solar Orbiter (SolO) is a Sun-observing satellite developed by the European Space Agency, it was launched on 10th Feb. 2020.  It has a unique elliptical orbit around the sun, with distances varying from 0.3 - 1 AU. The Spectrometer Telescope for Imaging X-rays (STIX) is one of the ten instruments onboard the Solar Orbiter.  It measures X-rays emitted during solar flares in the energy range of 4  150 keV and takes X-ray images by using an indirect imaging technique, based on the Moir effect.  Its detectors consist of thirty-two pixelated CdTe detectors with a total effective area of 6 cm^2.

More information about STIX can be found on the STIX data center website:  https://datacenter.stix.i4ds.net/


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32662
SUBJECT: GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
DATE:    22/10/10 15:38:59 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), V. Swain (IITB), G. Waratkar (IITB), K. Angail (IAO), V.
Bhalerao (IITB), G. C. Anupama(IIA), S. Barway (IIA) report on behalf of
the GIT team:

We observed Swift J1913.1+1946/GRB 221009A detected by Swift (S. Dichiara
et al., GCN #32632), Fermi (P. Veres et al., GCN #32636), INTEGRAL
(SPI-ACS) (Gotz et al., GCN #32660), and Konus-Wind (D. Svinkin et al., GCN
#32641), with 0.7m GROWTH-India Telescope (GIT). We obtained 200-sec
exposures in the g' and r' filters. We clearly detected the afterglow
candidate in our images at the position of Swift J1913.1+1946/GRB 221009A.
The photometric results follow as:

-------------------------------------------------------------------

 JD (mid) | T_mid-T0(hrs) | Filter | Magnitude (AB) |

-------------------------------------------------------------------

2459862.18181 | 2.19 | g' | 17.66 +/- 0.07 |

2459862.18451 | 2.25 | r' | 16.16 +/- 0.07 |

-------------------------------------------------------------------
The results are consistent with Lipunov et al., GCN #. 32634 and 32639;
Perley GCN #32638;  Broens, GCN #32640; Hu et al., GCN #32644; Belkin et
al. GCN #32645; de Wet et al. GCN #32646; Xu et al. GCN #32647; Odeh, GCN
#32649; Brivio et al. GCN # 32652. The magnitudes are calibrated against
PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic
extinction.

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree
field of view, set up by the Indian Institute of Astrophysics (IIA) and the
Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and
IUSSTF. It is located at the Indian Astronomical Observatory (Hanle),
operated by IIA. We acknowledge funding by the IITB alumni batch of 1994,
which partially supports the operations of the telescope. Telescope
technical details are available at
https://sites.google.com/view/growthindia/.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32663
SUBJECT: GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
DATE:    22/10/10 15:51:44 GMT
FROM:    Sergey Molkov at Space Research Inst., Moscow  <molkov@iki.rssi.ru>

I. Lapshov, S. Molkov, I. Mereminsky, A. Semena, V. Arefiev,
A. Tkachenko, A.Lutovinov (IKI RAS)
on behalf of the SRG/ART-XC team:

At 13:19:55 UT on 09 October 2022, the Mikhail Pavlinsky ART-XC
telescope on board the SRG observatory detected a strong burst
lasting few hundred seconds. Further analysis showed that the
source of emission was out of the field
of view of the instrument and the signal passed through the
telescope structure. We associate this event with a gamma-ray burst
GRB 221009A which was detected by Swift (Kennea et al. GCN #32635),
Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642),
Fermi-LAT (Bissaldi et al. GCN #32637, Pillera et al. GCN #32658),
the IPN (Svinkin et al. GCN #32641), SPI/ACS (Gotz et al. GCN #32660).

The ART-XC event corresponds to the second (brightest) burst episode
(see e.g. GCN #32642).
Since the radiation came out of the FoV, a prompt spectral analysis
of the event is impossible, however, due to the strong attenuation of
the signal passed through the surrounding matter, we register a
light curve shape that is practically not distorted by instrumental
effects such as deadtime, pile-up or telemetry problems. The light curve
in the full ART-XC energy range has a complex multi-peak structure
with two main maxima on 60th and 340th seconds from the start. The
event duration is near of 550 seconds.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32664
SUBJECT: GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
DATE:    22/10/10 16:21:51 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997@gmail.com>

I observed the optical afterglow of the extremely bright GRB 221009A =
Swift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using
0.61-m f/6.5 Corrected Dall-Kirkham telescope of Burke-Gaffney
Observatory (Lane, 2018, RTSRE, 1, 119) on 2022-10-10. Twelve images
with exposures of 300 seconds and IÑ filter were obtained, midtime of
the first image is 02:06:45 UTC (11h56m after the trigger), midtime of
the last image is 03:09:02 UTC (12h58m after the trigger).

I clearly detected the afterglow and measured (aperture photometry,
without deblending) following magnitudes of the afterglow from
comparison to transformed (from Lupton 2005 formula) magnitudes of
nearby stars from the Pan-STARRS DR1 catalogue (Chambers et al.,
2016):

Time (UTC)//Ic magnitude//Error
02:06:45  15.54  0.12
02:12:20  15.60  0.10
02:17:55  15.54  0.11
02:23:29  15.60  0.11
02:29:04  15.64  0.12
02:34:38  15.59  0.11
02:41:08  15.67  0.11
02:46:43  15.69  0.10
02:52:18  15.69  0.11
02:57:53  15.64  0.12
03:03:27  15.70  0.13
03:09:02  15.92  0.13

Magnitudes were not corrected for Galactic extinction.

FITS files available here:
https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20769 and
https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20770

Stacked image: https://observatory.smu.ca/~bgo/research/GRB_221009A.jpg

F. D. Romanov (AAVSO member, observer code: RFDA).


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32665
SUBJECT: GRB 221009A: Upper limits from a neutrino search with IceCube
DATE:    22/10/10 16:43:52 GMT
FROM:    Jessie Thwaites at IceCube/U Wisc-Madison  <thwaites@wisc.edu>

The IceCube Collaboration (http://icecube.wisc.edu/) reports:


IceCube has performed a search for track-like muon neutrino events arriving from the direction of GRB 221009A (GCN Circular 32632<https://gcn.gsfc.nasa.gov/gcn3/32632.gcn3> (Swift);  32636<https://gcn.gsfc.nasa.gov/gcn3/32636.gcn3> (Fermi-GBM)) in a time range of -1 hour/+2 hours from the initial trigger reported by Fermi-GBM (T0=2022-10-09 13:16:59.99 UTC) during which IceCube was collecting good quality data. Zero track-like events are found coincident with the position of the GRB. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 3.9 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum have energies in the approximate energy range between 800 GeV and 1 PeV.


A subsequent search was performed including 2 days of data centered on the Fermi-GBM trigger (2022-10-08 13:16:59.99 UTC to 2022-10-10 13:16:59.99 UTC). In this case, we report a p-value of 1.0, consistent with background expectation. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 4.1 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law.


The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can

be reached at roc@icecube.wisc.edu<mailto:roc@icecube.wisc.edu>.


[1] IceCube Collaboration, R. Abbasi  et al., ApJ 910 4 (2021)


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32667
SUBJECT: GRB 221009A: Lulin SLT-40cm optical observations
DATE:    22/10/10 20:05:50 GMT
FROM:    Ting-Wan Chen at MPE  <janet.chen@astro.su.se>

T.-W. Chen (Stockholm), D. B. Malesani (Radboud Univ. and DAWN/NBI), S. Yang (Stockholm), W.-J. Hou, C.-C. Ngeow, Y.-C. Pan, H.-Y. Hsiao, C.-S. Lin, and J.-K. Guo (IANCU) report:

We observed the field of GRB 221009A (a.k.a. Swift J1913.1+1946; Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., GCN 32637; Veres et al., GCN 32636; Lesage et al., GCN 32642; Gotz et al., GCN 32660), using the SLT-40cm at Lulin Observatory, Taiwan, to obtain g,r,i,z-band images as part of the Kinder collaboration (Chen et al., AstroNote 2021-92).

Observations started at 12:25 UT on 10 of October 2022 (MJD = 59862.518), 1.04 days after the Fermi GBM trigger time. The images were combined from 2 frames with 150 sec exposure time for each band, taken under variable seeing conditions (2".5 average) and at an airmass of 1.3.

We used aperture photometry to measure the transient brightness without template subtraction, and derived the following preliminary magnitudes and 3-sigma limits (all in the AB system):

g > 18.33 mag,
r = 18.67 +/- 0.16 mag,
i = 17.38 +/- 0.09 mag, and
z = 16.60 +/- 0.09 mag.

Given magnitudes are calibrated against Pan-STARRS1 field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 1.40 mag in the direction of the counterpart (Schlafly & Finkbeiner 2011).


GRB_name: GRB221009A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32668
SUBJECT: Konus-Wind detection of GRB 221009A
DATE:    22/10/10 20:18:09 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 extraordinary bright GRB 221009A
(Fermi-GBM detection: Veres et al. GCN Circ 32636, Lesage et al. GCN Circ 32642;
Fermi-LAT detection: Bissaldi et al. GCN Circ 32637;
IPN triangulation: Svinkin et al. GCN Circ 32641;
AGILE/MCAL detection detection: Ursi et al., GCN Circ 32650)
triggered Konus-Wind (KW) at T0=47821.648 s UT (13:17:01.648).

The burst light curve starts with a FRED-like initial pulse (IP)
that lasts from ~T0-1 s to ~T0+25 s. The IP is followed by an extremely
bright multi-peaked emission in the interval from ~T0+170 s to ~T0+600 s,
where a preliminary-estimated count rate reaches several hundred counts/s.
The emission at this stage is seen up to at least ~15 MeV.
The pulsed phase of the burst evolves to a steadily decaying emission tail,
which is visible in the KW data for more than 10000 s.

The preliminary Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB221009_T47821/

A time-averaged spectrum of the IP (measured from T0 to T0+28.842 s)
is best fit in the 20 keV - 15 MeV range by a power law with exponential
cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.62(-0.04,+0.05) and Ep = 975(-332,+712) keV (chi2 = 80/98 dof).
The fluence in this time interval is estimated to (2.4 Â± 0.3)x10^-05 erg/cm^2
and a 64-ms peak energy flux, measured from T0 + 5.760 s,
to (6.2 Â± 0.7)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

A time-averaged spectrum at the onset of the brightest phase of the event
(measured from T0+180.48 to T0+200.064 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 = -1.09 (-0.01,+0.01),
the high energy photon index beta = -2.60 (-0.06,+0.06),
the peak energy Ep = 1060 (-30,+31) keV, chi2 = 161/97 dof.
The fluence in this time interval is estimated to (8.8 Â± 0.1)x10^-04 erg/cm^2

The brightness of the main burst episode doesn't allow to perform
the standard KW spectral analysis of the emission at this stage of the event.
However, using the latter spectrum and a count rate light curve in the 80-320 keV range
with preliminary dead-time corrections applied, we obtain a rough estimate
of the fluence of the event in the interval from T0 to T0+600 s of ~0.052 erg/cm^2,
which is the highest value observed for GRBs for almost 28 years of the KW operation.
Further analysis of this extraordinary event is ongoing and
the results will be reported eslsewhere.

Assuming the redshift z=0.151 (de Ugarte Postigo et al., GCN 32648)
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 a high,
but reasonable value of ~3.0x10^54 erg.
The rest-frame peak energy of the spectrum Ep,z is estimated to ~1150 keV.
With these preliminary values, GRB 221009A perfectly fits the
'Amati' relation 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/GRB221009_T47821/GRB221009A_rest_frame.pdf

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


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32669
SUBJECT: GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
DATE:    22/10/10 20:34:25 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

Edgar Vidal, WeiKang Zheng and Alexei V. Filippenko (UC Berkeley)

report on behalf of the KAIT GRB team:


We observed the field of GRB 221009A (=Swift J1913.1+1946; Dichiara et al.,

GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi
et al.,

GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650;

Lesage et al., GCN 32642; Gotz et al., GCN 32660) with the 1-m Nickel
telescope

located at Lick observatory, California. Observations started about 15.73
hours

after the burst. Filtered B,V,R and I band images were taken with each
exposure

time of 300s. We detect the reported optical afterglow and measure its
brightness

with the following mag calibrated to the APASS catalog.


B = 20.18 +/- 0.2

V = 18.94 +/- 0.1

R = 17.59 +/- 0.1

I = 16.29 +/- 0.1


Additional images were also obtained with the 0.76-m Katzman Automatic
Imaging

Telescope (KAIT) also located at Lick Observatory. A set of clear (roughly
R)

band images were taken and the measured magnitude is consistent with the
above

Nickel R band magnitude.


GRB_name: GRB221009A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32671
SUBJECT: GRB 221009A: Continued Swift/XRT observations
DATE:    22/10/10 22:17:35 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), J.P. Osborne
(U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E.
Ambrosi  (INAF-IASFPA) , B. Sbarufatti (PSU), D.N. Burrows (PSU) and
M. Williams (PSU), report on behalf of the Swift-XRT team:

Swift XRT has continued to observe GRB 221009A  from 159s to 100 ks
after the BAT trigger. The WT-mode spectrum for the afterglow was
given in GCN 32651.

The lightcurve can be best modelled as a four-component power law decay with:
Alpha_1 : 2.6 (+0.4, -0.7)
Tbreak_1: 177.4 (+2.0, -9.6)
Alpha_2 : 0.144 (+0.022, -0.026)
Tbreak_2: 610 (+84, -78)
Alpha_3 : 0.31 (+0.04, -0.03)
Tbreak_3: (4.06 [+0.23, -0.19]) Ã— 10^3
Alpha_4 : 1.357 (+/-0.010)

With T0 the BAT trigger time.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01126853.

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


GRB_name: GRB221006A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32674
SUBJECT: GRB 221006A: CALET Gamma-Ray Burst Monitor detection
DATE:    22/10/11 05:22:49 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1@lsu.edu>

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

The long GRB 221006A (MAXI/GSC detection: Mihara et al.,
GCN Circ. 32626) was marginally detected in the ground analysis
of the CALET Gamma-ray Burst Monitor (CGBM) data near the 
MAXI trigger time at 00:57:09 UTC on October 6, 2022.  
The burst signal was seen by only HXM detectors.

The burst light curve shows a faint signal which starts at T+0.8 sec,
peaks at T+9.8 sec and ends at T+26.8 sec.  The T90 and T50 
durations measured by the HXM2 data are 24.0 +/- 2.0 sec and 
14.0 +/- 2.0 sec (7-100 keV), respectively.  The highest significance
during the burst is 4.6 sigma at T+15.8 sec with HXM2 data in the 7 - 10 keV band.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1349052973/

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


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32676
SUBJECT: GRB 221009A: NOEMA mm detection
DATE:    22/10/11 09:09:27 GMT
FROM:    Antonio de Ugarte Postigo at OCA  <deugarte@oca.eu>

A. de Ugarte Postigo (OCA), Michael Bremer (IRAM),
C. C. Thoene (ASU-CAS), M. Michalowski (AOI-AMU)
K. Misra (ARIES), S. Antier (OCA), D. A. Kann (Goethe 
Univ.), J. F. Agui Fernandez (IAA-CSIC), L. Resmi (IIST), 
S. Martin (ALMA), D. A. Perley (LJMU) and S. Schulze 
(Uni. of Stockholm) report,

We observed the afterglow of GRB 221009A (Dichiara et al., 
GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., 
GCN 32637; Veres et al., GCN 32636; Lesage et al., GCN 
32642) with NOEMA at 90 and150 GHz starting at 16:32 UT 
of the 10th of October, (27.35 hr after the Fermi GBM trigger; 
Veres et al., GCN 32636). The afterglow is strongly detected 
at 90 GHz with a flux of ~15 mJy. This is significantly below 
the extrapolation of the data reported at lower frequencies in 
previous GCNs (Bright et al. GCN 32653; Farah et al., GCN 
32655), indicating that our observations are beyond the peak 
Frequency, and that the earlier observations may have been 
affected by a reverse shock that has already faded.


GRB_name: GRB221009A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32677
SUBJECT: LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
DATE:    22/10/11 09:21:54 GMT
FROM:    Judith Racusin at GSFC  <judith.racusin@nasa.gov>

Yong Huang, Shicong Hu, Songzhan Chen,  Min Zha, Cheng Liu, Zhiguo Yao and
Zhen Cao report on behalf of the LHAASO experiment

We report the observation of GRB 221009A, which was detected by Swift (Kennea
et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642),
Fermi-LAT (Bissaldi et al. GCN #32637), IPN (Svinkin et al. GCN #32641) and so on.

GRB 221009A is detected by LHAASO-WCDA at energy above 500 GeV, centered at
RA = 288.3, Dec = 19.7 within 2000 seconds after T0, with the significance above
100 s.d., and is observed as well by LHAASO-KM2A with the significance about 10 s.d.,
where the energy of the highest photon reaches 18 TeV.

This represents the first detection of photons above 10 TeV from GRBs.

The LHAASO is a multi-purpose experiment for gamma-ray astronomy (in the energy
band between 10^11 and 10^15 eV) and cosmic ray measurements.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32678
SUBJECT: GRB 221009A: BlackGEM optical observations
DATE:    22/10/11 09:47:33 GMT
FROM:    Paul Groot at Radboud University Nijmegen  <p.groot@astro.ru.nl>

P.J. Groot (Radboud/UCT/SAAO), P.M. Vreeswijk (Radboud), R. Ter Horst
(NOVA), S.D. Bloemen (Radboud), P.G. Jonker (Radboud/SRON), S. de Wet
(UCT), D.B. Malesani (Radboud and DAWN/NBI), D. Pieterse (Radboud)
report on behalf of the BlackGEM consortium:

During commissioning the BlackGEM Unit Telescope 3 (BG3-Opal), located
at ESO La Silla, Chile, observed the optical counterpart of GRB221009A
(Dichiara et al., GCN 32632, Lesage et al. GCN 32642, Lipunov et al.,
32634) on 2022-10-11 in a series of 60s exposures in the q,u,z,g,i,r,q
bands. No debiasing or flatfielding was performed.

The optical counterpart is detected in q,z,i:
2022-10-11 00:47UT q = 18.98 +/- 0.09 +/- 0.05 (T0+35h30m)
2022-10-11 00:50UT z = 16.92 +/- 0.05 +/- 0.03 (T0+35h33m)
2022-10-11 00:54UT i = 17.92 +/- 0.06 +/- 0.02 (T0+35h37m),
where the first uncertainty is the statistical uncertainty and the
second is the uncertainty on the zeropoint photometric calibration. T0
is taken as the Fermi/GBM trigger time 2022-10-09 13:17UT (Lesage et
al., GCN 32642). All magnitudes are in the AB system.

BlackGEM is an array of wide-field telescopes designed, built and
operated by a consortium consisting of Radboud University, the
Netherlands Research School for Astronomy NOVA, KU Leuven, the
University of Manchester, Tel Aviv University, the Weizmann Institute,
the Hebrew University of Jerusalem, the University of Potsdam, Texas
Tech University, the University of California at Davis, the Danish
Technical University and the Armagh Observatory and Planetarium.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32679
SUBJECT: GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
DATE:    22/10/11 10:03:35 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  <filipp.romanov.27.04.1997@gmail.com>

I observed the optical afterglow of the extremely bright GRB 221009A =
Swift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using
telescope T24 (0.61-m f/6.5 reflector + CCD) of iTelescope.Net in
Sierra Remote Observatory (Auberry, California, USA) on 2022-10-11.

Two images (exposures 300 seconds, BINx1) were obtained with Ic
filter, midtime of the stacked image is 06:12:42 UT (1d16h02m after
the trigger).

I clearly detected the afterglow and measured (aperture photometry,
without deblending) following magnitude: 17.1 Ic +/- 0.2 from
comparison to transformed (from Lupton 2005) magnitudes of nearby
stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016).

Magnitude was not corrected for the Galactic extinction.

Stacked image available here:
https://www.flickr.com/photos/filipp-romanov/52419866941

F. D. Romanov (AAVSO member, observer code: RFDA).


GRB_name: GRB221009A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32680
SUBJECT: Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
DATE:    22/10/11 10:37:56 GMT
FROM:    Sandro Mereghetti at IASF-Milano/INAF  <sandro.mereghetti@inaf.it>

Andrea Tiengo (IUSS Pavia), Fabio Pintore (INAF IASF Palermo), Sandro
Mereghetti, Ruben Salvaterra (INAF IASF Milano)  on behalf of a larger
collaboration report:





Swift/XRT observed GRB221009A (GCN #32632, #32635, GCN #32636, #32637) in
PC mode three times (Obs.ID: 01126853004, 01126853005, 01126853006) between
2022-10-10 14:08:49 UT  and 2022-10-11 01:22:52 UT, for a net exposure time
of 7464.5 s.


The stacked Swift/XRT image in the 0.3-10 keV energy band shows the
presence of a complex system of at least 9 bright expanding rings with
radii from about 2.5 to 7.5 arcmin. We adopted the method described in
Tiengo & Mereghetti (2006, A&A 449, 203) to derive the following distances
of the dust clouds: 179.3 +/- 0.7 pc, 290 +/- 5 pc, 406.2 +/- 0.9 pc, 467.6
+/- 1.5 pc, 554 +/- 2 pc, 714 +/- 1 pc, 1094 +/- 24 pc,  2092 +/- 22 pc and
3635 +/- 36 pc.


GRB_name: GRB221011A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32681
SUBJECT: GRB 221011A: Fermi GBM Final Real-time Localization
DATE:    22/10/11 11:01:47 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 10:51:19 UT on 11 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221011A (trigger 687178284.149696 / 221011452).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 196.4, Dec = 0.6 (J2000 degrees, equivalent to J2000 13h 05m, 0d 36'), with a statistical uncertainty of 1.0 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/2022/bn221011452/quicklook/glg_skymap_all_bn221011452.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221011452/quicklook/glg_healpix_all_bn221011452.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221011452/quicklook/glg_lc_medres34_bn221011452.gif


GRB_name: GRB221006A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32682
SUBJECT: GRB 221006A: Swift ToO observations
DATE:    22/10/11 11:26:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the MAXI GRB 221006A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021524

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: GRB221009A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32683
SUBJECT: GRB 221009A: Upper limits from HAWC 8 hours after trigger
DATE:    22/10/11 12:04:14 GMT
FROM:    Hugo Ayala at Pennsylvania State University  <hgayala@psu.edu>

Hugo Ayala  (PSU) reports on behalf of the HAWC
collaboration (http://www.hawc-observatory.org/collaboration)
reports observations of GRB 221009A which was detected by
Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636,
Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637),
and the IPN (Svinkin et al. GCN #32641).

We use the position measured by Fermi LAT (GCN #32658), located at:
RA = 288.282, Dec = 19.495 (0.027 deg 90% containment radius)

This position started transiting over HAWC at 21:19:57 UTC on 2022/10/09
(~8 hours after the trigger time)  and ended at 03:42:07 UTC on 2022/10/10.

Assuming a power law spectra with index of -2.0 we found no significant
detection in the region. We proceeded to calculate the 95% upper limit on
the flux at 1 TeV: 4.16e-12 (TeV cm2 s)^-1

HAWC is a very-high-energy gamma-ray observatory operating in Central
Mexico at latitude 19 deg. north. Operating day and night with over
95% duty cycle, HAWC has an instantaneous field of view of 3.14 sr and
surveys <5/6 of the sky every day. It is sensitive to gamma rays from
300 GeV to 100 TeV.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32684
SUBJECT: GRB 221009A: Sintez-Newton/CrAO optical observations
DATE:    22/10/11 13:01:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI, HSE), S. Nazarov (CrAO), A. Pozanenko (IKI),  N. Pankov 
(HSE)  report on behalf of IKI GRB FuN:

We observed GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632; 
Kennea and Williams, GCN  32635; Veres et al., GCN  32636; Bissaldi et 
al., GCN  32636; Svinkin et al., GCN 32641; Piano et al., GCN 32657; 
Pillera et al., GCN 32658;  Gotz et al., GCN 32660;  Frederiks et al., 
GCN 32668)  with Sintez-Newton 350mm f/5 telescope equipped with QHY600M 
camera and g'r'i'z' filters.  Observation started on 2022-10-10 (UT) 
17:24:54. The series consists of images with an exposure of 120 s in 
r'-filter.

In the stacked image we clearly detect the optical afterglow (e.g. 
Dichiara et al., GCN 32632; Lipunov et al., GCN 32634; Perley GCN 32638; 
Hu et al., GCN 32644; Belkin  et al., GCN 32645; Kuin et al., GCN 32656; 
Kim et al., GCN 32670). Preliminary photometry of the afterglow is following


Preliminary photometry of the stacked images is following

Date       UT start   t-T0    Filter Exp.    OT    err   UL(3)
                      (mid, days)       (s)
2022-10-10 17:24:54   1.16293  r'    40*120  18.43 0.10  20.9

The photometry is based on nearby PS1 stars


GRB_name: GRB221009A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32685
SUBJECT: GRB 221009A: Detection by GRBAlpha
DATE:    22/10/11 13:24:38 GMT
FROM:    Jakub Ripa at Masaryk University  <245487@mail.muni.cz>

J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk 
U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly 
Observatory), M. Dafcikova, F. Munz, N. Husarikova, J.-P. Breuer, M. 
Topinka, 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 extraordinarily bright long-duration GRB 221009A (Swift/BAT 
detection: Kennea et al., GCN 32635; Fermi-GBM detection: Veres et al., 
GCN 32636; Fermi-LAT detection: Pillera et al., GCN 32658; INTEGRAL 
SPI/ACS detection: Gotz et al., GCN 32660; Konus-Wind detection: 
Frederiks et al., GCN 32668; IPN triangulation: Svinkin et al., GCN 
32641; LHAASO detection: Huang et al., GCN 32677) at a redshift of z = 
0.151 (de Ugarte Postigo et al., GCN 32648) was detected by the GRBAlpha 
1U CubeSat (Pal et al. Proc. SPIE 2020).

The GRB did not saturate our detector and the peak count rate reached 
~22 000 count/s in the ~70-890 keV energy band (for a 50 cm^2 detector) 
at 2022-10-09 13:20:52 UTC. The duration of the GRB was >250s. GRBAlpha 
was flying above the northern polar region with elevated background 
levels. The end part of the GRB was recorded while passing the outer Van 
Allen radiation belt.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB221009A_GCN_GRBAlpha.pdf

GRBAlpha, launched on 2021 March 22, is a demonstration mission for a 
future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its 
detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) 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, we are continuously 
upgrading the on-board data acquisition software stack. 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: GRB221009A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32686
SUBJECT: GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
DATE:    22/10/11 13:37:44 GMT
FROM:    Alberto J. Castro-Tirado at IAA-CSIC  <ajct@iaa.es>

A. J. Castro-Tirado, R. Sanchez-Ramirez, Y.-D. Hu, M.D. 
Caballero-Garcia, M. A. Castro Tirado, E. Fernandez-Garcia, I. 
Perez-Garcia (IAA-CSIC), G. Lombardi (GTC, IAC), S. B. Pandey (ARIES), 
J. Yang (NJU) and B.-B. Zhang (NJU) on behalf of a larger collaboration, 
report:

Following the detection of the extraordinarily bright GRB 221009A 
detected by Swift, Fermi, MAXI/GSC, INTEGRAL (SPI-ACS), Konus-Wind, the 
IPN, AGILE/MCAL, SolO/STIX, SRG/ART-XC, CALET and GRBAlpha (Dichiara et 
al. GCNC 32632, Veres et al. GCNC 32636, Bissaldi et al. GCNC 32637, 
Svinkin et al. GCNC 32641, Negoro et al. ATEL 15651, Ursi et al. GCNC 
32650, Xiao et al GCNC 32661, Lapshov et al. GCNC 32663, Cannady et al. 
GCNC 32674, Ripa et al. GCNC 32685), we triggered the 10.4m Gran 
Telescopio de Canarias (GTC) equipped with Optical System for Imaging 
and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) in La 
Palma (Spain), starting on Oct 9, 22:19 UT (~9 hrs after the GBM 
trigger). Spectroscopy was obtained with both the R1000B (2x900s) and 
R1000R (2x300s) grisms, covering the 363-1000 nm spectral range. A red 
continuum is noticeable, in agreement with earlier reports by Perley 
(GCNC 32638) and Xu et al. (GCNC 32647). The GTC spectrum clearly shows 
the Ca II H & K absorption doublet implying a redshift of z=0.1505, 
consistent the value derived from X-shooter/VLT (de Ugarte Postigo et 
al. GCNC 32648).  With this redshift of z= 0.1505, a time-averaged peak 
energy of 2.52 MeV and a total fluence of 2.6e-2 erg cm^-2,  we found 
that the main emission episode (between 174 and 700 s post trigger) of 
GRB 221009A is consistent with the Type II (collapsar origin; Zhang et 
al, 2007, 2009) bursts in the Ep-Eiso diagram (Amati et al. 2002).

We thank the staff at GTC for their excellent support.


GRB_name: GRB221009A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32688
SUBJECT: GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
DATE:    22/10/11 14:12:57 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

H. A. Krimm (NSF), S. D. Barthelmy (GSFC),
S. Dichiara (PSU), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
T. Sakamoto (AGU), M. Stamatikos (OSU)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+1371 sec from the recent
telemetry downlink, we report further analysis of BAT GRB 221009A
(trigger #1126853 and #1126854) (Dichiara et al., GCN Circ. 32632).
The BAT ground-calculated position is
RA, Dec = 288.254, 19.809 deg which is
   RA(J2000)  =  19h 13m 00.9s
   Dec(J2000) = +19d 48' 34.1"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 9%.

The mask-weighted light curve shows a flat and long-lasting emission
that may have started before the burst came into the BAT FOV at T-26 s.
The burst emission seems to end at ~T+1320 s, however, we cannot rule
out the possibility that the emission extends beyond the available
event data that end at T+1371 s. The lower limit of T90 (15-350 keV)
is 1068.40 +- 13.34 sec (estimated error including systematics).

The time-averaged spectrum from T+103.3 s to T+1338.7 s sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 2.08 +- 0.03.  The fluence in the 15-150 keV band
is 7.4 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured
from T+776.47 sec in the 15-150 keV band is 1.9 +- 0.3 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1126853/BA/


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32690
SUBJECT: GRB 221009A: planned observation with the Imaging X-ray Polarimetry Explorer (IXPE)
DATE:    22/10/11 15:56:24 GMT
FROM:    Michela Negro at CREST/NASA-GSFC/UMBC  <mnegro1@umbc.edu>

Michela Negro, Alberto Manfreda and Nicola Omodei on behalf

of the IXPE Collaboration report that:


IXPE will begin observing GRB 221009A on 2022-10-11 at

23:34:28.40 UTC and will observe for 100k s.

The detailed weekly timeline for IXPE observations (which

currently includes the slew to GRB 221009A) can be found here:

https://ixpe.msfc.nasa.gov/for_scientists/weekly.html


The Imaging X-ray Polarimetry Explorer, commonly known as IXPE

is a space observatory with three identical telescopes designed

to measure the polarization of cosmic X-rays. The observatory,

which was launched on 9 December 2021, is an international

collaboration between NASA and the Italian Space Agency (ASI).


GRB_name: GRB221009A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32691
SUBJECT: GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
DATE:    22/10/11 16:05:23 GMT
FROM:    Volodymyr Savchenko at ISDC,U of Geneve  <savchenk@in2p3.fr>

Volodymyr Savchenko (UNIGE, EPFL), Carlo Ferrigno, Enrico Bozzo (UNIGE), 
D. Gotz (CEA Paris Saclay), S. Mereghetti (INAF/IASF Milano),  Antonio 
Martin Carrillo, Lorraine Hanlon (UCD), Elisabeth Jourdain, Jean-Pierre 
Roques (IRAP), Thomas Siegert (University of WÃ¼rzburg), Erik Kuulkers, 
Celia Sanchez (ESA)


Following the detection of the record-breaking GRB221009A by Swift/BAT 
(GCN #32632,#32635), Fermi/GBM (GCN #32636),
INTEGRAL/SPI-ACS (GCN #32660), we have performed INTEGRAL pointed 
observations of the GRB221009A location.

INTEGRAL pointed observation lasted from 2022-10-10T14:31:40 (T0 + 25.2 
hours, where T0 is 2022-10-09T13:17:00) to 2022-10-11T03:18:20 (T0 + 
38.0 hours) with a total exposure time of 30.2 ks (for ISGRI).

In the complete observation, the source is clearly detected in JEM-X1, 
JEM-X2 (3-30 keV), and ISGRI (28 - 80 keV), with S/N of 27.8, 27.3, 15.0 
respectively.

The joint JEM-X and ISGRI spectra can be satisfactorily modeled between 
3 and 80 keV with a single powerlaw of slope 2.15 +/- -0.07 (90% 
confidence) with a flux of 4.4e-10 +/- -2.1e-11 erg/cm2/s (3 - 80 keV).
This might indicate a single spectral component spanning from from hard 
X-ray to Fermi/LAT (GCN #32658).

Combination of bright Hard X-ray afterglow with gamma-ray emission was 
also found in GRB120711A (Martin-Carrillo et al. 2014 A&A 567, 84) and 
GRB130427A (Kouveliotou et al. 2013 ApJ 779L, 1K)
- in fact GRB221009A appears rather similar to GRB120711A, but at 10 
times smaller distance.

Within the relatively short JEM-X not ISGRI lightcurves, we do not 
observe any evidence for flux decrease.

Further INTEGRAL observations are scheduled between 2022-10-11 13:52:21 
and 2022-10-13 00:58:26. These observations will overlap with the 
planned observation of IXPE (GCN #32690).

We are grateful to the INTEGRAL Ground Segment team for quickly 
scheduling the observations.

Images and reduced data related to this publication can be found here: 
https://zenodo.org/record/7186289


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32692
SUBJECT: GRB 221009A: COATLI Detection of the Afterglow
DATE:    22/10/11 16:41:09 GMT
FROM:    Alan M Watson at UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Simone Dichiara (PSU), Rosa L.
Becerra (UNAM), Tzveti Dimitrova (ASU), OcÃ©lotl LÃ³pez (UNAM), Diego
GonzÃ¡lez (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM),
Margarita Pereyra (UNAM), Eleonora Troja (UTV/ASU) and report:

We observed the field of the bright GRB 220930A (Dichiara et al., GCN
Circ. 32632, Veres et al., GCN Circ. 32636) with the COATLI 50-cm
telescope and HUITZI f/8 imager at the Observatorio AstronÃ³mico Nacional
on the Sierra de San Pedro MÃ¡rtir (http://coatli.astroscu.unam.mx) from
2022-10-11 06:05 UTC to 06:39 UTC (40.2 hours after the trigger),
obtaining a total of 405 seconds of exposure in each of the g, r, i, and
z filters.

At the position of the UVOT afterglow (Dichiara et al., GCN Circ.
32632), we detect a source with the following magnitudes and 3-sigma
upper limit:

g > 20.27

r = 19.48 +/- 0.13

i = 18.49 +/- 0.07

z = 17.92 +/- 0.08

Our photometry is calibrated against the Pan-STARRS1 catalog, is on an
approximate AB system, and is not corrected for Galactic extinction in
the direction of the GRB.

We thank the COATLI/HUITZI technical team and the staff of the
Observatorio AstronÃ³mico Nacional.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32693
SUBJECT: GRB 221009A: LCOGT Optical Afterglow Detection
DATE:    22/10/11 17:04:03 GMT
FROM:    Robert Strausbaugh at University of Minnesota  <rstrausb@umn.edu>

R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on
behalf of a larger collaboration:

We observed the GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632)
field with the LCOGT 1-meter Sinistro instrument at the Teide Observatory,
on Tenerife, on October 10, from 19:33 to 19:50 (corresponding to 29.38 to
29.66 hours from the GRB trigger time) with the SDSS g, r and i filters.

We performed a series of 3x100s exposures in each band.  We clearly detect
the optical transient at the UVOT coordinates (Dichiara et al., GCN 32632),
in r and i bands, and marginally in g-band (2-sigma detection), consistent
with other optical detections.

The following magnitudes are calculated using the Pan-STARRS catalog as
reference:

g = 20.87 +/- 0.36
r = 18.80 +/- 0.21
i = 17.77 +/- 0.20

These magnitudes are not corrected for galactic extinction.  Further
observations are planned.


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32694
SUBJECT: GRB 221009A: NICER follow-up observations
DATE:    22/10/11 18:41:54 GMT
FROM:    George A. Younes at George Washington U  <gyounes@email.gwu.edu>

W. Iwakiri (Chuo U.), G. K. Jaisawal (DTU Space), G. Younes
(NASA/GSFC/GWU), Z. Wadiasingh (UMCP, NASA/GSFC), S. Guillot (IRAP/CNRS),
K. C. Gendreau (NASA/GSFC), Z. Arzoumanian (NASA/GSFC), E. C. Ferrara
(UMCP, NASA/GSFC), T. Mihara (RIKEN), D. Pasham (MIT), J. M. Miller (Univ.
of Michigan), A. Sanna (Univ. of Cagliari), C. Malacaria (ISSI), C. B.
Markwardt (NASA/GSFC)

We report on initial NICER observations of the exceptionally bright GRB
221009A, at a redshift of 0.1505 (GCN #32648, #32686) and observed from
radio to TeV energies (GCNs #32632, #32635, #32636, #32641, #32658, #32661,
#32668, #32677, and ATels #15653, #15655, #15656, #15660, #15661). NICER
observed GRB 221009A intermittently from 2022 Oct 9 17:11 to Oct 11 00:12
UT, or 14.7 ksec to 126 ksec after the Fermi/GBM trigger time (GCN #32636).
During this period, NICER made 12 observations with exposure times ranging
from 40 to 400 sec each. The initial count rate registered with NICER is
1400 counts/s which declined to about 38 counts/s at the time of the last
observation reported here. From a preliminary analysis, we find that the
decline follows a power law with an index of -1.6. The 1-10 keV spectrum of
each observation is well reproduced by an absorbed power-law model with a
spectral index of about 2.0. We used the tbabs model with wilms abundance
in XSPEC (Wilms, Allen & McCray 2000) for an assumed Galactic absorption of
5.4 x 10^21 cm^-2 (Willingale et al. 2013; GCN #32651). The average column
density of these observations with the ztbabs model is 1.1 x 10^22 cm^-2 at
a redshift of 0.151 (GCN #32648). The absorbed (unabsorbed) flux in the 0.3
- 10 keV band declined from 6.1 x 10^-9 (1.3 x 10^-8) to 1.8 x 10^-10 (3.3
x 10^-10) erg/sec/cm^2.

NICER initially received notification of the GRB through OHMAN (On-orbit
Hookup of MAXI and NICER) at 14:10:57 UT on Oct 9, but poor visibility
delayed a prompt follow-up.  OHMAN is software on an International Space
Station laptop computer that provides a new automated triggering
capability, monitoring live MAXI data and communicating new transient
alerts to NICER for follow-up within minutes, visibility permitting. NICER
is continuing to monitor GRB 221009A.  Detailed temporal and spectral
analysis is ongoing.

The NICER schedule can be found at
https://heasarc.gsfc.nasa.gov/docs/nicer/schedule/nicer_sts_current.html.

NICER is a 0.2-12 keV X-ray telescope operating on the International Space
Station. The NICER mission and portions of the NICER science team
activities are funded by NASA.


GRB_name: GRB221009A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32695
SUBJECT: GRB 221009A: NuSTAR Detection 
DATE:    22/10/11 19:38:52 GMT
FROM:    Ryan Chornock at UC Berkeley  <chornock@berkeley.edu>

Daniel Brethauer (UC Berkeley), Brian Grefenstette (Caltech), Judith Racusin (NASA/GSFC), Raffaella Margutti (UC Berkeley), Kate D. Alexander (Arizona), Tom Barclay (NASA/GSFC), Edo Berger (Harvard), Eric Burns (LSU), Brad Cenko (NASA/GSFC), Yvette  Cendes (Harvard), Ryan Chornock (UC Berkeley), Tarraneh Eftekhari (Northwestern), Jamie Kennea (PSU), and Tanmoy Laskar (Utah) report:

NuSTAR began a Target of Opportunity observation of GRB 221009A (GCN #32632) on October 11, 2022 at 03:10:07 UTC, approximately 38 hours after the GBM Trigger (GCN #32642), with an exposure of 23.4 ks (PIs Racusin and Margutti).

The 3-79 keV spectrum is well fit by a power law with a photon index of Gamma= 1.81 +/- 0.01, which is consistent with the value inferred from Swift-XRT observations acquired during the same time window.  The corresponding unabsorbed flux is (3.37 +/- 0.02) e-10 erg/cm2/s (3-79 keV). Over the NuSTAR observation, the source X-ray flux declines by about 30%. However, preliminary analysis does not indicate a significant evolution of the 10-20 keV / 3-6 keV hardness ratio.

These findings are consistent with the hard X-ray afterglow observed by INTEGRAL JEM-X and ISGRI (GCN #32691) and support an absorbed simple power-law spectrum extending from soft X-ray to hard X-ray energies. 

Three additional NuSTAR monitoring observations are planned and are anticipated to occur on October 15th, 20th, and November 2nd.  We thank the NuSTAR SOC for promptly implementing these observations.


GRB_name: GRB220826B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32696
SUBJECT: GRB 220826B: Detection by GRBAlpha
DATE:    22/10/11 20:32:30 GMT
FROM:    Jakub Ripa at Masaryk University  <245487@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. 
Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, 
B. Csak (Konkoly Observatory), F. Munz, N. Husarikova, J.-P. Breuer, M. 
Topinka, 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 220826B (Fermi-GBM detection at 2022-08-26 
10:21:19.72 UT, trigger no. 683202084) was detected by the GRBAlpha 1U 
CubeSat (Pal et al. Proc. SPIE 2020).

The 5.0 sigma detection was confirmed at the peak time 2022-08-26 
10:21:20.4 UTC. The GRB has a T90 duration of 9 s.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB220826B_GCN.pdf

GRBAlpha, launched on 2021 March 22, is a demonstration mission for a 
future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its 
detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) 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, we are continuously 
upgrading the on-board data acquisition software stack. 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: GRB220829A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32697
SUBJECT: GRB 220829A: Detection by GRBAlpha
DATE:    22/10/11 20:33:57 GMT
FROM:    Jakub Ripa at Masaryk University  <245487@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. 
Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, 
B. Csak (Konkoly Observatory), F. Munz, N. Husarikova, J.-P. Breuer, M. 
Topinka, 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 220829A (Konus-Wind detection at 2022-08-29 
14:37:50.3 UT; INTEGRAL/SPI-ACS detection at 2022-08-29 14:37:52 UT) was 
detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020).

The 14.8 sigma detection was confirmed at the peak time 2022-08-29 
14:37:50.4 UTC. The GRB has a T90 duration of 6 s.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/GRB220829A_GCN.pdf

GRBAlpha, launched on 2021 March 22, is a demonstration mission for a 
future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its 
detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) 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, we are continuously 
upgrading the on-board data acquisition software stack. 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: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32700
SUBJECT: GRB 221009A/Swift J1913.1+1946: eMERLIN observations 
DATE:    22/10/12 12:47:01 GMT
FROM:    Lauren Rhodes at Oxford  <lauren.rhodes@physics.ox.ac.uk>

L. Rhodes, J. Bright, R. Fender (Oxford), and D.R.A. Williams (JBCA) report:



We observed the position of GRB 221009A (Swift J1913.1+1946; ATel #15650, ATel #15651) with the eMERLIN at 1.51GHz beginning at 17:55UT on 11th October for a total of 6 hours. OQ208 was used as the flux and bandpass calibrator while J1905+1943 was used as the complex gain calibrator.



We detect an unresolved source at a position consistent with the one reported in ATel #15651 with a (preliminary) flux density of ~4mJy.



We are in the process of obtaining further radio observations. We thank the e-MERLIN staff for the time allocation and their assistance with the observations.


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32705
SUBJECT: GRB 221009A: COATLI Continued Monitoring of the Afterglow
DATE:    22/10/12 15:23:25 GMT
FROM:    Alan M Watson at UNAM  <alan@astro.unam.mx>

Nat Butler (ASU), Alan M. Watson (UNAM), Simone Dichiara (PSU), Rosa L.
Becerra (UNAM), Tzveti Dimitrova (ASU), OcÃ©lotl LÃ³pez (UNAM), Diego
GonzÃ¡lez (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM),
Margarita Pereyra (UNAM), Eleonora Troja (UTV/ASU) and report:

We observed the field of the bright GRB 221009A (Dichiara et al., GCN
Circ. 32632, Veres et al., GCN Circ. 32636) with the COATLI 50-cm
telescope and HUITZI f/8 imager at the Observatorio AstronÃ³mico Nacional
on the Sierra de San Pedro MÃ¡rtir (http://coatli.astroscu.unam.mx) from
2022-10-12 04:00 UTC to 06:34 UTC (63.1 hours after the trigger),
obtaining a total of 7560 seconds of exposure in the i filter.

At the position of the UVOT afterglow (Dichiara et al., GCN Circ.
32632), we detect a source with the following magnitude:

i = 19.10 +/- 0.02

Our photometry is calibrated against the Pan-STARRS1 catalog, is on an
approximate AB system, and is not corrected for Galactic extinction in
the direction of the GRB.

Compared to our observations on the previous night (Watson et al., GCN
Circ. 32692), the decay has a power-law index of 1.24 +/- 0.13.

Further observations are planned.

We thank the COATLI/HUITZI technical team and the staff of the
Observatorio AstronÃ³mico Nacional.


GRB_name: GRB221009A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32707
SUBJECT: GRB 221009A/Swift J1913.1+1946: SMA observations
DATE:    22/10/12 18:54:52 GMT
FROM:    Lauren Rhodes at Oxford  <lauren.rhodes@physics.ox.ac.uk>

Lauren Rhodes (University of Oxford), Kuiyun Huang (CYCU/PCCU) and Yvette Cendes (Harvard) report on behalf of a larger collaboration:


We observed the field of the candidate gamma-ray burst GRB 221009A (Swift J1913.1+1946; ATel#15650, ATel#15651) with the Submillimeter Array (SMA) at 230.7GHz beginning at 03:27UT on 12 October 2022 for a total of 3.3 hours. Uranus was used as the flux calibrator, while 3c84 was used to calibrate the bandpass response. 1925+211 and mwc349a were used as interleaved complex gain calibrators.



We detect an unresolved source at a position consistent with the UVOT position reported in ATel #15650 at a (preliminary) flux density of 9.30 +/- 0.75mJy. Further observations are planned.



We thank the staff at the SMA for carrying out these observations.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32709
SUBJECT: GRB221009A: optical afterglow measurements from Konkoly Observatory
DATE:    22/10/12 22:29:55 GMT
FROM:    Jozsef Vinko at Konkoly Observator  <vinko@konkoly.hu>

J. Vinko, A. Bodi, A. Pal, L. Kriskovics, R. Szakats, K. Vida
(Konkoly Observatory, Hungary) report:

We observed the field of the bright GRB221009A (Dichiara et al., GCN #32632, Veres et al., GCN #32636)
with the RC80 robotic telescope at Piszkesteto Station of Konkoly Observatory on 2022 Oct 10.81 UT 
and Oct 12.85 UT, during inferior sky conditions. A series of 300 sec frames were collected through 
Sloan r'- and i' bands. The bright optical afterglow
(Lipunov et al. GCN #32634; Perley et al. GCN #32638; Broens GCN #32640; Hu et al. GCN #32644;
Belkin et al. GCN #32645; Wet et al. GCN #32646; Xu et al. GCN #32647; de Ugarte Postigo et al.
GCN #32648; Odeh GCN #32649; Brivio et al. GCN #32652; Kuin et al. GCN #32656;
Paek et al. GCN #32659; Kumar et al. GCN #32662; Romanov GCN #32664; Odeh GCN #32666;
Chen et al. GCN #32667; Vidal et al. GCN #32669; Kim et al. GCN #32670; Groot et al. GCN #32678;
Romanov GCN #32679; Castro-Tirado et al. GCN #32686; Watson et al. GCN #32692; Strausbaugh et al.
GCN #32693; Butler et al. GCN #32705)
was clearly detected on the stacked frames with the following magnitudes, calibrated
via nearby PS1 stars:

Date        UT-middle   t-T0(hr)  Exp(s)   r'(AB-mag)       i'(AB-mag)
2022-10-10  19:26:51    30.16     600      18.74 (0.12)     17.50 (0.08)
2022-10-12  20:18:24    79.02     300      20.58 (0.70)     18.74 (0.18)

These magnitudes are not corrected for galactic extinction.


GRB_name: GRB221006A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32710
SUBJECT: Afterglow limits of GRB 221006A from OHP
DATE:    22/10/12 22:49:00 GMT
FROM:    C. C. Thoene at HETH/IAA-CSIC  <christina.thoene@gmail.com>

R. Oâ€™Rourke Brogan (AIP), P. A. C. Cunha (Univ. do Porto/CAUP), G. Ma
(DAWN/NBI) and C. C. Thoene (ASU-CAS) report:

We observed the field of the MAXI GRB 221006A (GCN 32626, Mikhara et al;
GCN 32628, Sbarufatti et al.) using the 1.2m telescope at the Observatoire
de lâ€™Haute Provence. Observations started on Oct. 06, 2022 at 20:49 UT,
~20h after the GRB under nearly full Moon conditions.

In a combined exposure of 2600s in R-band we do not detect a counterpart at
any of the positions of the three possible candidates (Source 1: RA
22:29:24.52, DEC +15:38:02.8; Source 2: RA 22:28:58.99, DEC +15:42:49.6;
Source 3: RA 22:29:23.07, DEC +15:41:38.6) down to a limiting magnitude of
R = 22 mag (3 sigma).

At the position of source 2, confirmed to be fading with a significance of
4.6 sigma (https://www.swift.ac.uk/xrt_products/TILED_GRB00108/), there are
two underlying galaxies also present in the SDSS, which we call G1 and G2.
Our image shows a combined magnitude of R=21.2 +/- 0.4 for the two
galaxies. The objects show no evidence of excess emission, which is
consistent with our upper limit. G1 has a distance of 0.5 arcsec and G2 of
3.5 arcsec from the X-ray candidate afterglow, making G1 the likely host of
GRB 221006A.

We thank the NEON observing school and the support of the 1.2m telescope
operator Stephane Favard for obtaining these data.


GRB_name: GRB221013A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32724
SUBJECT: GRB 221013A: Fermi GBM Final Real-time Localization
DATE:    22/10/13 00:52:49 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 00:42:20 UT on 13 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221013A (trigger 687314545.232582 / 221013029).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 255.2, Dec = -3.5 (J2000 degrees, equivalent to J2000 17h 00m, -3d 30'), with a statistical uncertainty of 24.6 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/2022/bn221013029/quicklook/glg_skymap_all_bn221013029.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013029/quicklook/glg_healpix_all_bn221013029.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013029/quicklook/glg_lc_medres34_bn221013029.gif


GRB_name: GRB221013B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32726
SUBJECT: GRB 221013B: Fermi GBM Final Real-time Localization
DATE:    22/10/13 02:33:57 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 02:23:28 UT on 13 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221013B (trigger 687320613.487128 / 221013100).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 220.8, Dec = -36.3 (J2000 degrees, equivalent to J2000 14h 43m, -36d 17'), with a statistical uncertainty of 14.6 degrees.

The angle from the Fermi LAT boresight is 109.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013100/quicklook/glg_skymap_all_bn221013100.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013100/quicklook/glg_healpix_all_bn221013100.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221013100/quicklook/glg_lc_medres34_bn221013100.gif


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32727
SUBJECT: GRB 221009A: GMG observation
DATE:    22/10/13 03:01:54 GMT
FROM:    Jirong Mao at Yunnan Obs  <jirongmao_obs@ynao.ac.cn>

J. Mao, K.-X. Lu, X.-H. Zhao, and J.-M. Bai (YNAO) report:




We observed the field of GRB 221009A (Dichiara et al. GCN 32632) with the 2.4-meter optical

telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at

UT 14:34:40, 12, Oct. 2022, about 3 days after the trigger. We marginally detected the

afterglow. The preliminary magnitude was measured to be z~18.9. We caution that the magnitude

has a relatively large uncertainty due to the very poor seeing.  


GRB_name: GRB221009A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32729
SUBJECT: GRB 221009A: Sayan observatory 1.6-m telescope observations
DATE:    22/10/13 07:08:22 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

I. Zaznobin, R. Burenin (IKI), M. Eselevich (ISTP SB RAS)

report:

The field of an extraordinarily bright GRB 221009A, detected by Swift
(Kennea et al., GCN 32635), Fermi GBM (Veres et al., GCN 32636),
SRG/ART-XC (Lapshov, et al., GCN 32663), Konus-Wind (Frederiks et al.,
GCN 32668), and others, was observed with the Sayan observatory
(Mondy) 1.6-m telescope AZT-33IK, using a CCD photometer, starting at
2022/10/10 13:38 UT, i.e. approximately 24.4 hours after the burst.

The optical transient found earlier (Dichiara et al., GCN 32632,
Lipunov et al., GCN 32634, Perley et al., GCN 32638, Belkin et al.,
GCN 32645, and others), was observed in griz filters with the
following magnitudes:

g = 20.57 +- 0.08
r = 18.84 +- 0.02
i = 17.80 +- 0.02
z = 16.99 +- 0.02

The decay in OT brigtness in all filters is observed during
approximately 2 hours of our observations.

Spectra of the OT in 3700--10000A wavelength range were also obtained
using ADAM low and medium resolution spectrograph. The analysis of
these data is underway.


GRB_name: GRB221009A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32730
SUBJECT: GRB 221009A: MITSuME Okayama optical observation
DATE:    22/10/13 07:58:56 GMT
FROM:    Yuri Imai at Tokyo Inst of Tech  <imai@hp.phys.titech.ac.jp>

M. Sasada, Y. Imai, K. L. Murata, R. Hosokawa, M. Niwano, I.Takahashi,
M. Tateda, N. Ito, S. Sato, N. Higuchi, Y. Yatsu, and N. Kawai (Tokyo
Tech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 221009A (Dichiara et al. #32632, Kennea
et al. #32635, Veres et al. #32636, Bissaldi et al. #32637, Perley et
al. #32638, Broens et al. #32640, Svinkin et al. #32641, Lesage et al.
#32642, Karambelkar et al. #32643, Hu et al. #32644, Belkin et al.
#32645, Wet et al. #32646, Xu et al. #32647, Postigo et al. #32648,
Ursi et al. #32650, Kennea et al. #32651, Brivio et al. #32652, Bright
et al. #32653, Durbak et al. #32654, Farah et al. #32655, Piano et al.
#32657, Pillera et al. #32658, Paek et al. #32659, Gotz et al. #32660,
Xiao et al.#32661, Kumar et al. #32662, Lapshov et al. #32663, Romanov
et al. #32664, The IceCube Collaboration et al. #32665, Odeh et al.
#32666, Chen et al. #32667, Frederiks et al. #32668, Vidal et al.
#32669, Kim et al. #32670, Tohuvavohu et al. #32671, Postigo et al.
#32676, Huang et al. #32677, Groot et al. #32678, Romanov et al.
#32679, Tiengo et al. #32680, Ayala et al. #32683, Belkin et al.
#32684, Ripa et al. #32685, Castro-Tirado et al. #32686, Krimm et al.
#32688, Negro et al. #32690, Savchenko et al. #32691, Watson et
al.#32692, Strausbaugh et al. #32693, Iwakiri et al. #32694, Brethauer
et al. #32695, Rhodes et al. #32700, Butler et al. #32705, Rhodes et
al. #32707, Vinko et al. #32709, Mao et al. #32727, Zaznobin et al.
#32729) with the optical three color (g', Rc, and Ic) CCD cameras
attached to the MITSuME 50 cm telescope Okayama.

The observation with a series of 60 sec exposures started at
2022-10-09 9:51:38 UT (0.857 day after the Swift detection). We
stacked the images with good conditions. Here we report a Ic-band
magnitude by the forced-photometry at the Swift/UVOT position
(Dichiara et al. GCN Circular #32632), and the 5-sigma limits of the
stacked images in the g' and Rc bands.

T0+[day] |MID-UT | T-EXP[sec] | magnitudes of forced-photometry
------------------------------------------------------------------------------------------------
0.9320 | 2022-10-10 11:39:09| 8340 | g'>18.3, Rc>17.0, Ic=17.1+/-0.2
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used PS1 catalog for flux calibration. The magnitudes are expressed
in the AB system. The images were processed in real-time through the
MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73,
Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).


GRB_name: GRB221006A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32731
SUBJECT: GRB 221006A: Swift-XRT afterglow detection
DATE:    22/10/13 08:31:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

B. Sbarufatti (INAF-OAB), J. D. Gropp (PSU), S. Dichiara (PSU), J.A.
Kennea (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U.
Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
MAXI-detected burst GRB 221006A (Mihara et al. GCN Circ. 32626). The
observations now extend from T0+37.8 ks to T0+595.5 ks. 

Of the sources reported by Sbarufatti et al. (GCN Circ. 32628), "Source
2" is fading with >3-sigma significance, and is therefore likely the
GRB afterglow. Using 1256 s of PC mode data and 2 UVOT images, we find
an enhanced XRT position (using the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue): RA, Dec = 337.24578,
+15.71379 which is equivalent to:

RA (J2000): 22h 28m 58.99s
Dec(J2000): +15d 42' 49.6"

with an uncertainty of 3.2 arcsec (radius, 90% confidence). This
position is 4.8 arcmin from the MAXI position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.01 (+0.34, -0.25).

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021521.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00108.

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


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32738
SUBJECT: GRB221009A: LCOGT Continued Observations - Optical Upper Limits
DATE:    22/10/13 16:00:24 GMT
FROM:    Robert Strausbaugh at University of Minnesota  <rstrausb@umn.edu>

R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on
behalf of a larger collaboration:

We observed the GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632)
field with the LCOGT 1-meter Sinistro instrument at the McDonald
Observatory, Texas, USA site, on October 13, from 03:34 to 04:18
(corresponding to 84.60 to 85.50 hours from the GRB trigger time) with the
SDSS g, r, and i filters.

We performed a series of 3x300s exposures in each band.  We do not detect
the optical transient at the UVOT coordinates (Dichiara et al., GCN 32632),
in any bands.

The following upper limits are calculated using the Pan-STARRS catalog as
reference:

g > 22.3
r > 21.4
i > 20.5

These magnitudes are not corrected for galactic extinction.


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32739
SUBJECT: GRB 221009A: Lowell Discovery Telescope Afterglow Detection
DATE:    22/10/13 17:07:17 GMT
FROM:    Brendan O'Connor at UMD  <oconnorb@umd.edu>

B. O'Connor (UMD/GWU), S. B. Cenko (NASA/GSFC), E. Troja (UTV/ASU),
S. Dichiara (PSU), A. Kutyrev (NASA/GSFC), S. Veilleux (UMD),
J. Durbak (UMD), on behalf of a larger collaboration:

We performed target of opportunity observations of GRB 221009A
(Dichiara et al., GCN 32632, Veres et al., GCN 32636)
with the 4.3m Lowell Discovery Telescope in Happy Jack, AZ.
Observations began on October 13, 2022 at 03:09:27 UT corresponding
to ~3.6 d after the GRB. We obtained images in the griz filters at
an airmass ~1.2 with seeing ~1.2".

The afterglow is clearly detected in all filters. We obtain the
following magnitudes calibrated against the PS1 catalog:

r = 20.44 +/- 0.02 AB mag
i = 19.37 +/- 0.01 AB mag

Compared to observations at 63 hr (Watson et al., GCN 32705)
the temporal decay has a power-law index of about -0.9,
shallower than observed in X-rays.

These magnitudes are not corrected for Galactic extinction.

We thank the staff of the Lowell Observatory for assistance
with these observations.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32740
SUBJECT: GRB 221009A: MeerKAT detection
DATE:    22/10/13 17:34:58 GMT
FROM:    Tanmoy Laskar at U of Bath  <tanmoylaskar@gmail.com>

T. Laskar (University of Utah), K. D. Alexander (Arizona), E. Ayache
(Stockholm), E. Berger (Harvard), S. Bhandari (ASTRON/JIVE), J. Bright
(Oxford), R. Chornock (UC Berkeley), D. Coppejans (Warwick), H. van Eerten
(Bath), W. Fong (Northwestern), P. Groot (Radboud), R. Margutti (UC
Berkeley), C.G. Mundell (Bath), P. Schady (Bath), G. Schroeder
(Northwestern), and S. de Wet (Cape Town) report:

"We observed GRB 221009A (Dichiara et al. GCN 32632) with the MeerKAT radio
telescope array beginning on 2022 October 10 19:10 UTC (1.3 d after the
burst). Preliminary analysis reveals a radio counterpart with 1.284 GHz
flux density of ~ 2.1 mJy at position:

RA (J2000) = 19:13:03.47 +/- 0.04"
Dec (J2000) = 19:46:25.08 +/- 0.06"

This position is consistent with the optical position (Dichiara et al., GCN
32632; Lipunov et al., GCN 32634). Further observations are planned.

The MeerKAT telescope is operated by the South African Radio Astronomy
Observatory, which is a facility of the National Research Foundation, an
agency of the Department of Science and Innovation."


GRB_name: GRB221009A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32741
SUBJECT: GRB 221009A: search for neutrinos with KM3NeT 
DATE:    22/10/13 18:57:37 GMT
FROM:    Damien Dornic at CPPM,France  <dornic@cppm.in2p3.fr>

The KM3NeT Collaboration (https://www.km3net.org/) reports:<br><br>
 
Using the data from the online fast processing chain, the KM3NeT Collaboration has performed a dedicated search for track-like muon neutrino events arriving from the direction of GRB 221009A (Dichiara et al. GCN 32632 (Swift);  Veres et al. GCN 32636 (Fermi-GBM)). The search covers the time range of [T0-50s, T0+5000s], with T0 being the trigger time reported by Fermi-GBM (T0=2022-10-09 13:16:59.00 UTC), during which both KM3NeT detectors were collecting good quality data. However, the GRB location was above the KM3NeT horizon (mean elevation of about ~40deg) during the search time window, significantly reducing the point-like source sensitivity. In both detectors, zero events were observed in the search window, while o(0.1) were expected from the background. The online fast processing uses preliminary calibrations and detector alignment, which will be superseded in a future elaborated analysis.<br><br>
 
A parallel search has been performed in the MeV range (Eur.Phys.J.C 82 (2022) 4, 317) without any significant neutrino coincidence.<br><br>
 
KM3NeT is a large undersea (Mediterranean Sea) infrastructure hosting two neutrino detectors, sensitive to burst of supernova neutrinos in the MeV range and to astrophysical neutrinos in the GeV-PeV energy range: ARCA at high energy and ORCA at low energy. A total of 21 and 11 detection lines are currently in operation in ARCA and ORCA, respectively. 


GRB_name: GRB221006A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32742
SUBJECT: MAXI GRB 221006A: Redshifts of the possible host galaxies
DATE:    22/10/13 19:01:48 GMT
FROM:    C. C. Thoene at HETH/IAA-CSIC  <christina.thoene@gmail.com>

P. A. C. Cunha (Univ. do Porto/CAUP), G. Ma (DAWN/NBI), R. Oâ€™Rourke Brogan
(AIP), C. C. Thoene (ASU-CAS), A. de Ugarte Postigo (OCA, Nice), D. A. Kann
(Goethe Univ.), J. F. Agui Fernandez (IAA-CSIC), L. Izzo (DARK/NBI), J.P.U.
Fynbo (DAWN/NBI), N. R. Tanvir (Univ. Leicester), M. Blazek (Prague) and D.
Garcia Alvarez (GTC) report:

We observed the possible host galaxies of the MAXI GRB (GCN 32626, Mikhara
et al) underlying the candidate afterglow at RA 22:28:58.99, DEC
+15:42:49.6  (GCN 32628, Sbarufatti et al., confirmed to be fading in GCN
32731, Sbarufatti et al.), which we already reported in GCN 32710,
(Oâ€™Rourke Brogan et al.). Observations were obtained with OSIRIS at the
10.4m GTC telescope in La Palma starting on Oct. 10, 2022 at 20:10 UT with
a total exposure time of 3x600s using the R1000R grism (5100-10100Ã…) and a
1 arcsec slit aligned across both putative hosts.

We clearly detect the traces of both galaxies in the combined spectrum and
determine redshifts of z=0.731 for G1 and z=0.464 for G2 based on emission
lines of [OII], [OIII] Hb and Ha. Based on the distance from the X-ray
afterglow candidate we determined G1 to be the likely host of GRB 221006A
(GCN 32710, Oâ€™Rourke Brogan et al.) and hence assume a redshift of z=0.731
for its possible host galaxy.

We acknowledge two very enjoyable weeks at the NEON observing school during
which these follow-up observations were obtained.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32743
SUBJECT: GRB221009A: RTT-150 optical observations
DATE:    22/10/13 20:12:07 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

Ilfan Bikmaev (KFU, AST, Kazan), Irek Khamitov (TUG, Antalya, KFU, Kazan),
Eldar Irtuganov (KFU, AST, Kazan), Mark Gorbachev (KFU, AST, Kazan),
Nail Sakhibullin (KFU, AST, Kazan), Rodion Burenin (IKI, Moscow)

report:

We have performed optical observations of the OT GRB221009A (Dichiara
et al., GCN 32632, GCNs 32635, 32636,32636, 32641, 32657, 32658,
32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679, 32680,
32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695, 32700,
32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739) by
using 1.5-meter joint Russian-Turkish telescope (RTT-150, TUBTAK
National Observatory, Antalya, Turkey) in October 10-12, 2022. We
used TFOSC instrument for photometry in griz filters and low
resolution spectroscopy in the 3800 - 8870 A range. During 3
consecutive nights starting 27.6 hours since the trigger we make
series of images in griz with 600 sec exposures each.

We clearly see the OT in all frames. Photometric data were calibrated
using nearby PS1 star. Results of our photometry are given in the
Table.

JD               T-T0    Filter  mag   merr
                 (hours)   
2459863.2056537  27.653  g      20.13  0.08
2459863.2131298  27.832  r      18.65  0.02
2459863.2205018  28.009  i      17.52  0.01
2459863.2278493  28.185  z      16.81  0.01
2459863.3452805  31.004  g      20.44  0.25
2459863.3681597  31.553  r      18.81  0.05
2459863.3760363  31.742  i      17.69  0.02
2459863.3840870  31.935  z      16.99  0.01   
2459864.1923863  51.334  r      19.53  0.04
2459864.2002009  51.522  i      18.40  0.02
2459864.2076914  51.702  z      17.69  0.02
2459864.2153146  51.884  g      21.15  0.21
2459864.3645166  55.465  r      19.67  0.11
2459864.3728065  55.664  i      18.49  0.04
2459864.3804310  55.847  z      17.72  0.03
2459865.2047148  75.630  i      18.82  0.03
2459865.2122502  75.811  r      20.03  0.06
2459865.2198393  75.993  z      18.20  0.04
2459865.2273203  76.173  i      19.02  0.07
2459865.2347618  76.351  r      19.97  0.08
2459865.2422699  76.531  z      18.19  0.05
2459865.2497386  76.711  i      19.09  0.10
2459865.2571590  76.889  r      20.07  0.19
2459865.2646685  77.069  z      18.40  0.08
2459865.2720521  77.246  i      18.95  0.07
2459865.2795044  77.425  r      20.32  0.17
2459865.2869724  77.604  z      18.26  0.03
2459865.2943683  77.782  i      18.93  0.04
2459865.3092743  78.140  z      18.23  0.03
2459865.3167266  78.318  i      18.93  0.04
2459865.3241129  78.496  r      20.17  0.12
2459865.3315775  78.675  z      18.23  0.04
2459865.3389639  78.852  i      18.92  0.04
2459865.3507442  79.135  r      20.26  0.16
2459865.3583217  79.317  z      18.30  0.04
2459865.3733491  79.677  r      20.24  0.19
2459865.3809028  79.859  z      18.18  0.04

Two series of low resolution (12 A) spectra were obtained in October
10, UT = 17:43 - 19:54 and in October 11, UT = 17:24 - 20:32.  Their
analysis is underway.


GRB_name: GRB221009A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32744
SUBJECT: GRB221009A: Detection as sudden ionospheric disturbances (SID)
DATE:    22/10/13 21:42:27 GMT
FROM:    Doug Welch at McMaster University  <welch@physics.mcmaster.ca>

P.W. Schnoor (Kiel Longwave Monitor, Germany), P. Nicholson
(Todmorden, UK), D.L. Welch (McMaster University, Canada)

A sudden disturbance of the Earth's ionosphere (SID) was observed by the
Kiel Longwave Monitor (Germany) and a VLF-Monitor at Todmorden (near
Manchester, UK) coincident with the detection of GRB221009A (SWIFT, 
#32635).

This SID was seen as a sudden increase or decrease in the signal strengths
from radio transmitters below 100 kHz (19.6 to 63.9 kHz; VLF/LF) received
at Kiel and Todmorden.

These naval transmitting stations are located at France, Germany, Iceland,
Israel, Italy, Japan (Okinawa), United Kingdom and United States.

Note: This is not a radio detection of GRB221009A; this disturbance was
caused by the prompt X-rays and/or gamma-rays from GRB221009A
ionizing the upper atmosphere and modifying the radio propagation
properties of the waveguide between ground and ionosphere.

According to the SWIFT-BAT refined analysis (RA, Dec = 288.254, 19.809 deg,
GCN #32688) GRB221009A was above local horizon at both receiving sites
(2022-10-09, 13:16:59 UT).

Kiel:      az = 101.8, el = 32.9 deg
Todmorden: az = 94.6,  el = 28.3 deg

Plots of the SID detection are available at the following URLs:

Kiel
https://www.qsl.net/df3lp/grb221009/KLM_grb221009a_magnitudes.png

Todmorden
http://abelian.org/vlf/grb221009a-DHO.png
http://abelian.org/vlf/grb221009a-NAA.png
http://abelian.org/vlf/grb221009a-NSY.png

The Kiel Longwave Monitor consists of a set of very low frequency radio
receivers attached to a crossed pair of loop antennas (16m^2 each),
monitoring the radio spectrum from 1.0 to 96.0 kHz at 50Hz-steps.

The VLF-monitor at Todmorden consists of a set of very low frequency radio
receivers attached to a crossed pair of loop antennas (20m^2 each) and a
vertical antenna, monitoring the radio spectrum below 100 kHz.


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32745
SUBJECT: GRB221009A: Ionospheric disturbance observed in India
DATE:    22/10/13 21:48:26 GMT
FROM:    Doug Welch at McMaster University  <welch@physics.mcmaster.ca>

Authors: A. Guha (Centre for Lightning and Thunderstorm Studies (CeLTS), 
Department of Physics, Tripura University, India.), P. Nicholson 
(Todmorden, UK)

We report the observation of a sudden disturbance of radio propagation 
in the very low frequency (VLF) band between 18kHz and 23kHz coincident with
GRB221009A. Affected were phase and amplitude of MSK ("Minimum Shift 
Keying") signals from naval transmitters monitored by the Indian 
Lightning Detection Network.

The GRB221009A exceeded 70 degrees elevation at all receiver sites.

https://ildn.in/gallery/ILDN-GRB221009A-VTX3.png
https://ildn.in/gallery/ILDN-GRB221009A-NWC.png
https://ildn.in/gallery/ILDN-GRB221009A-NDT.png

The Indian Lightning Detection Network (ILDN) is an experimental network 
of 10 VLF receivers operated by collaborating institutions for lightning 
location and observation of other VLF phenomena on the Indian subcontinent.


GRB_name: GRB221009A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32746
SUBJECT: GRB 221009A: Gamma-ray Detection by SIRI-2
DATE:    22/10/14 00:18:42 GMT
FROM:    Lee Mitchell at Naval Research Laboratory  <lee.mitchell@nrl.navy.mil>

L. J. Mitchell, B. F. Phlips, (Naval Research Laboratory), W.N. Johnson (Technology Service Corporation)



The SIRI-2 gamma-ray spectrometer (Mitchell et al. 2019, Proc. SPIE 11118) detected the bright long-duration GRB 221009A detected by Swift/BAT (Dichiara et al., GCN 32632, Kennea et al., GCN 32635), Fermi-GBM (Lesage et al., GCN 32642, Veres et al., GCN 32636), Fermi-LAT (Bissaldi et al. GCN 32637, Pillera et al., GCN 32658), AGILE-MCAL (Ursi et al., GCN 32650), AGILE-GRID (Piano et al. GCN 32657), INTEGRAL SPI/ACS (Gotz et al., GCN 32660), Konus-Wind (Frederiks et al., GCN 32668), at a redshift of z = 0.151 (de Ugarte Postigo et al., GCN 32648; Castro-Tirado et al., GCN 32686).



The GRB was 19.9 degrees off-axis from the un-collimated instrument. With 10-second binning, the background-subtracted peak count rates in the 300-7000 keV energy range were ~65e3 count/s and ~24e3 count/s from 2022-10-09 13:20:51-13:21:11  and 13:21:11-13:21:41 UTC, respectively, coinciding with the previously-reported brightest two gamma-ray peaks.  De-convolving the instrument response for the incident angle, the photon spectra for both peaks are consistent with a power law slope of -1.7 +/- 0.1.





SIRI-2 (Mitchell et al. 2019, Proc. SPIE 11118) was launched on 2021 DATE aboard the DoD Space Test Program's STPSat-6. It consists of seven hexagonal europium-doped strontium iodide (SrI2:Eu) scintillation detectors (each 3.81 cm by 3.81 cm), with a frontal area of 66 cm2, and read out by a SiPM array, covering the energy range of ~300 keV to ~7000 keV.


GRB_name: GRB221014A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32747
SUBJECT: GRB 221014A: Fermi GBM Final Real-time Localization
DATE:    22/10/14 00:40:24 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 00:29:46 UT on 14 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221014A (trigger 687400191.292052 / 221014021).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 90.0, Dec = 19.0 (J2000 degrees, equivalent to J2000 06h 00m, 19d 00'), with a statistical uncertainty of 47.3 degrees.

The angle from the Fermi LAT boresight is 65.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221014021/quicklook/glg_skymap_all_bn221014021.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221014021/quicklook/glg_healpix_all_bn221014021.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221014021/quicklook/glg_lc_medres34_bn221014021.gif


GRB_name: GRB221009A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32748
SUBJECT: GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger
DATE:    22/10/14 01:09:54 GMT
FROM:    Zi-Qing Xia at Purple Mountain Observatory  <xiazq@pmo.ac.cn>

Zi-Qing Xia, Yun Wang, Qiang Yuan and Yi-Zhong Fan (Purple Mountain Observatory) report:

We have analyzed the long-term (MET: 687014224, 687139205) Fermi-LAT gamma-ray observations above 100 MeV of GRB 221009A, a burst characterized by its huge power, a low redshift as well as the highest energy photons (Kennea et al. GCN #32635, Veres et al. GCN #32636, Lesage et al. GCN #32642, Bissaldi et al. GCN #32637, Svinkin et al. GCN #32641, Huang et al. GCN #32677).

We find a 397.7 GeV photon at 0.27 degree from the LAT localization of GRB 221009A (RA = 288.282, Dec = 19.495, from Pillera et al. GCN #32658), arriving at 33554 seconds after the Fermi-GBM trigger. The location of this event is RA = 288.252, Dec = 19.763, which is close to the LHAASO localization of GRB 221009A (RA = 288.3, Dec = 19.7, from Huang et al. GCN #32677).

From a preliminary analysis, the 397.7 GeV event is found to be associated with GRB 221009A at a significance level of >3 sigma, which would be the most energetic GRB photon detected by Fermi-LAT so far (The previous records are a 99.3 GeV photon from GRB 221009A at an early time and a 95 GeV photon from GRB 130427A). Pre-GRB 221009A, just two photon events around 100 GeV had been observed by Fermi-LAT within 0.5 degree of GRB 221009A, suggesting a rather low chance coincidence probability of being a background. Furthermore, the GeV emission of GRB 221009A lasted more than one day.

The detection of such a high energy photon at t~0.4 day after the GRB trigger seems to favor the inverse compton origin rather than the synchrotron radiation (Fan et al. 2013 ApJ, 776, 95; https://arxiv.org/abs/1305.1261), which can reach very-high-energy domain in particular for the nearby luminous GRBs (Xue et al. 2009 ApJ, 703, 60; https://arxiv.org/abs/0907.4014).


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32749
SUBJECT: GRB221009A: Gemini-South Optical Afterglow Detection
DATE:    22/10/14 01:58:41 GMT
FROM:    Jillian Rastinejad at Northwestern Univ.  <jillianrastinejad2024@u.northwestern.edu>

J. Rastinejad and W. Fong (Northwestern) report on behalf of a larger collaboration:

We observed the location of GRB 221009A (Dichiara et al. GCN 32632) with the Gemini Multi-Object Spectrograph (GMOS) mounted on Gemini-South under Program GS-2022B-DD-103 (PI: Rastinejad). We obtained 7x60-sec imaging in i-band at a mid-time of 2022 October 14 00:40:12 UT  (4.437 days post-burst), at a median airmass of 1.9. We clearly detect the optical afterglow. Calibrated to Panstarrs, we measure a brightness of i ~ 19.8 AB mag at seeing < 0.8'', not corrected for Galactic extinction. This is consistent with recently reported measurements (e.g. Bikmaev et al. GCN 32743) and indicates significant fading from the i-band measurement of 15.58 +/- 0.03 AB mag reported by de Wet et al. (GCN 32646) at 0.178 days. 

Further observations are planned to monitor the variability of the source. We thank Jennifer Andrews, Janice Lee, and additional Gemini staff for the rapid DDT approval, as well as the planning and execution of these observations.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32750
SUBJECT: GRB 221009A: Gemini-South Infrared Afterglow Detection
DATE:    22/10/14 03:46:29 GMT
FROM:    Brendan O'Connor at UMD  <oconnorb@umd.edu>

B. O'Connor (UMD/GWU), E. Troja (UTV/ASU), S. Dichiara (PSU),
J. Gillanders (UTV), S. B. Cenko (NASA/GSFC):

We performed target of opportunity observations of GRB 221009A
(Dichiara et al., GCN 32632, Veres et al., GCN 32636)
with the FLAMINGOS-2 spectrograph mounted on the Gemini-South
telescope. Observations began on October 13, 2022 at 23:58:42 UT
corresponding to ~4.4 d after the GRB. We obtained images in the
JHK filters with a total exposure of 60 s in each. The target
was at airmass 1.75 under seeing of ~0.7".

The afterglow is clearly detected in the JHK filters. We obtain
the following magnitudes calibrated against the 2MASS catalog:

J = 17.93 +/- 0.03 AB mag
H = 17.23 +/- 0.05 AB mag
K = 16.69 +/- 0.02 AB mag

Compared to previous nIR photometry (Brivio et al., GCN 32652,
Durbak et al. GCN 32654), our observation yields a power-law
decay with index ~ -1.4. This is steeper than reported in the
optical (O'Connor et al., GCN 32739) and consistent with that
observed in X-rays.

These magnitudes are not corrected for Galactic extinction.

Further infrared observations are planned.

We thank the staff (Janice Lee, Jennifer Andrews, and Jeong-Eun Heo)
of the Gemini Observatory for rapidly  approving and scheduling
these observations.


GRB_name: GRB221009A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32751
SUBJECT: GRB 221009A: HEBS detection
DATE:    22/10/14 10:09:17 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

J. C. Liu, Y. Q. Zhang, S. L. Xiong, C. Zheng, C. W. Wang, W. C. Xue, R. 
Qiao, W. J. Tan, D. L. Zhang, X. Q. Li, X. Y. Wen, W. X. Peng, L. M. 
Song, S. J. Zheng, D. Y. Guo, X. B. Li, X. Ma, Y. Huang, X. Y. Zhao, P. 
Wang, J. Wang, Z. Zhang, Y. Q. Du, J. Liang, Y. Q. Lu, H. Wu, W. H. Yu, 
S. Xiao, C. Cai, P. Zhang, B. Li, Z. H. An, M. Gao, K. Gong, X. J. Liu, 
Y. Q. Liu, X. L. Sun, Y. B. Xu, S. Yang, P. Y. Feng, J. Z. Wang, F. 
Zhang, G. Chen, F. J. Lu, S. N. Zhang (IHEP) report on behalf of GECAM 
and HEBS teams:

During the commissioning phase, HEBS detected the prompt emission of the
extraordinarily bright burst GRB 221009A, which was also observed by
Fermi/GBM (Lesage et al., GCN 32642, Veres et al., GCN 32636),
Swift/BAT (Dichiara et al., GCN 32632, Kennea et al., GCN 32635)
Insight-HXMT/HE (Tan et al., Atel 15660),
Fermi/LAT (Bissaldi et al. GCN 32637, Pillera et al., GCN 32658),
AGILE/MCAL (Ursi et al., GCN 32650), AGILE/GRID (Piano et al. GCN 32657),
INTEGRAL SPI/ACS (Gotz et al., GCN 32660),
Konus-Wind (Frederiks et al., GCN 32668), SIRI-2 (Mitchell et al., GCN 
32746),
and LHAASO (Huang et al., GCN 32677).

At the beginning of the burst (2022-10-09T13:17:00.050 UTC, denoted as 
T0), HEBS was in the high latitude region where the in-flight triggering 
of HEBS was disabled to eliminate false triggers caused by particle 
background. However, one gamma-ray detector (i.e. GRD01) and one charged 
particle detector (i.e. CPD02) are set to collect data normally during 
this region. The full burst of GRB 221009A prompt emission was well 
monitored by HEBS. The incident angle to GRD01 is about 70 deg during 
the prompt emission.

Despite of the extreme brightness, the GRB 221009A main burst (T0+180s 
to T0+270s) was clearly observed by HEBS without data saturation. The 
dead-time is reasonable and the pulse pileup effect is negligible for 
the low gain readout channel of GRD01.

The dead-time corrected light curves of HEBS could be found at:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/HEBS-GRB221009A.png

 From the 50 ms light curve, we note that there are complicated spiky 
structures during the main peaks. All results above are preliminary. 
Refined analysis is ongoing and will be reported later.

HEBS is an all-sky monitor for gamma-ray transients in 10 keV to 5 MeV 
aboard the Space advanced technology demonstration satellite (SATech-01) 
satellite, which is funded and built by Chinese academic of sciences, 
and was launched on July 27, 2022. Both the payload and the science 
operation of HEBS are inherited from GECAM mission (made of two 
mini-satellites, GECAM-A and GECAM-B), and thereafter HEBS is also 
called GECAM-C.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32752
SUBJECT: GRB221009A: RTT-150 optical observations
DATE:    22/10/14 11:03:17 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

Ilfan Bikmaev (KFU, AST, Kazan), Irek Khamitov (TUG, Antalya, KFU, Kazan),
Eldar Irtuganov (KFU, AST, Kazan), Mark Gorbachev (KFU, AST, Kazan),
Nail Sakhibullin (KFU, AST, Kazan), Rodion Burenin (IKI, Moscow)

report:

We have performed additional optical observations of the OT GRB221009A
(Dichiara et al., GCN 32632, GCNs 32635, 32636,32636, 32641, 32657,
32658, 32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679,
32680, 32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695,
32700, 32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739,
32740, 32743, 32746, 32749, 32750) by using 1.5-meter joint
Russian-Turkish telescope (RTT-150, TUBITAK National Observatory,
Antalya, Turkey) and TFOSC instrument in October 13, 2022. We made
series of images in riz filters with 600 sec exposures each.

We clearly see the OT in all frames. Photometric data were calibrated
using nearby PS1 star. Results of our photometry are given in the
Table:

JD                T-T0    Filter  mag   merr
                 (hours)   
2459866.2034967   99.601  r      20.53  0.09
2459866.2115203   99.793  i      19.51  0.06
2459866.2189183   99.971  z      18.63  0.05
2459866.2263488  100.149  r      20.63  0.09
2459866.2339414  100.332  i      19.41  0.05
2459866.2413937  100.510  z      18.76  0.05
2459866.2488331  100.689  r      20.71  0.15
2459866.2562889  100.868  i      19.52  0.05
2459866.2636921  101.046  z      18.69  0.04
2459866.2711805  101.225  r      20.54  0.10
2459866.2786139  101.404  i      19.44  0.04
2459866.2862528  101.587  z      18.75  0.04
2459866.2937201  101.766  r      20.55  0.12
2459866.3010995  101.943  i      19.45  0.05
2459866.3088004  102.128  z      18.74  0.05
2459866.3162909  102.308  r      20.74  0.16
2459866.3238331  102.489  i      19.43  0.05
2459866.3314625  102.672  z      18.83  0.05
2459866.3389523  102.852  r      20.90  0.23
2459866.3464004  103.031  i      19.48  0.06
2459866.3558217  103.257  z      18.74  0.05
2459866.3633150  103.437  r      20.86  0.27
2459866.3707428  103.615  i      19.50  0.07
2459866.3798291  103.833  z      18.71  0.06

RTT-150 light curves for 4 nights observations are shown in the Figure:

https://www.srg.cosmos.ru/static/images/grb/lc_grb221009A_RTT150.jpg


Power law decay indexes based on RTT-150 griz observations, taking in
account our data obtained earlier (Bikmaev et al., GCN 32743) are as
follows:

g:   -1.42 +- 0.20
r:   -1.47 +- 0.07
i:   -1.40 +- 0.04
z:   -1.38 +- 0.04

Our measurements of the OT power law decay agree well with that
measured in infrared bands (O'Connor et al., GCN 32750, Brivio et al.,
GCN 32652, Durbak et al. GCN 32654), obtained during nearly the same
periods of OT observations.

The mean value of (r - z) color indicates no any significant changes
in the optical spectrum slope during four nights of our observations.


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32753
SUBJECT: GRB 221009A: OHP optical observations
DATE:    22/10/14 12:40:52 GMT
FROM:    Benjamin Schneider at CEA  <benjamin.schneider@cea.fr>

B. Schneider (CEA Paris-Saclay), C. Adami (LAM), E. Le Floc'h, 
D. Turpin, D. GÃ¶tz (CEA Paris-Saclay) S. D. Vergani, A. Saccardi 
(GEPI, Observatoire de Paris), S. Basa, A. Le Van Suu (LAM) report 
on behalf of a larger collaboration:

We observed the field of GRB 221009A (Dichiara et al., GCN 32632; 
Veres et al., GCN 32636) using the T120cm telescope at Observatoire 
de Haute-Provence (France). Four exposures were obtained in the 
r band (2x300s + 2x600s), three exposures in the i band (3x600s) 
and the z band (1x300s + 2x900s) from 2022 12 Oct 19:11:05 UT to 
2022 12 Oct 20:41:23 UT (mid time ~78h after trigger). In the 
combined frame, we clearly detect the source in the three filters 
and obtain the following magnitudes:

r = 20.23 Â± 0.09 mag (AB)
i = 18.91 Â± 0.11 mag (AB)
z = 18.35 Â± 0.13 mag (AB)

The photometric calibration was performed using nearby stars from 
the PanSTARRS catalog and magnitudes are not corrected for Galactic 
extinction.

These values are consistent with observations obtained at a similar 
time by Bikmaev et al. (GCN 32743).

Further observations using the MISTRAL instrument mounted on the 
T193-OHP are planned for the coming nights.

We acknowledge the excellent support from Observatoire de Haute Provence, 
in particular FranÃ§ois Huppert and JÃ©rome Schmitt.


GRB_name: GRB221009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32754
SUBJECT: GRB 221009A: IXPE preliminary upper limits of X-ray polarization 
DATE:    22/10/14 12:58:40 GMT
FROM:    Michela Negro at CRESST/NASA-GSFC/UMBC  <mnegro1@umbc.edu>

Michela Negro, Alberto Manfreda, Nicola Omodei and 
Fabio Muleri report on behalf of the IXPE Collaboration 

IXPE performed the first observation of X-ray polarization of a 
GRB afterglow in the 2 â€” 8 keV energy range.
IXPE observed GRB 221009A from 2022-10-11T23:34:28UTC to 
2022-10-14T00:45:31UTC  for an effective exposure of 100 ks. 

From a quick-look analysis of the *image-, time- and energy- averaged
low-level instrument data (prior to pipeline processing at the IXPE
SOC), we report:

Polarization degree (PD) < 11.1% upper limits are derived with 99% C.L.

These results are preliminary. The IXPE Collaboration will report 
the final results in a forthcoming publication.

The Imaging X-ray Polarimetry Explorer, commonly known as IXPE 
is a space observatory with three identical telescopes designed 
to measure the polarization of cosmic X-rays. X-ray polarimetry 
enabled by IXPE can be performed in energy-, time-, and 
angle-resolved fashions. The observatory, which was launched 
on 9 December 2021, is an international collaboration between 
NASA and the Italian Space Agency (ASI).

[Editor's note: Reformatted at the request of the submitter.]


GRB_name: GRB221009A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  32755
SUBJECT: GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
DATE:    22/10/14 14:29:16 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

P. Dâ€™Avanzo, M. Ferro, R. Brivio, M. G. Bernardini, D. Fugazza, S. Campana, S. Covino (INAF-OAB), V. Dâ€™Elia (ASI/SSDC), 
M. De Pasquale (Messina Univ.), D. B. Malesani (Radboud Univ. and DAWN/NBI), A. Melandri (INAF-OAR), E. Palazzi (INAF-OAS), 
S. Piranomonte (INAF-OAR), A. Rossi (INAF-OAS), B. Sbarufatti, G. Tagliaferri (INAF-OAB) on behalf of the REM team and of the 
CIBO collaboration, report:

We continued to observe the field of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; 
Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) with the REM 60cm robotic telescope located at the ESO 
premises of La Silla (Chile). The observations were carried in the optical and NIR bands, from about 0.4 to 3.5 days after the GBM trigger, 
with a nightly cadence. 

A refined analysis of the first REM epoch reveals that the H-band photometry reported in Brivio et al. (GCN Circ. 32652) is affected from 
contamination from a field star located at an angular separation of about 5" from the NIR afterglow. 
We report here an updated value of H = 12.62 +/- 0.02 mag (Vega, calibrated against the 2MASS catalogue) at 0.4 days after the GBM trigger. 

Inspection of the H- and z-band afterglow light curves obtained with REM reveals evidence for a steepening in the decay after about 1 day. 
We carried out a fit of the 0.3 - 10 keV Swift/XRT afterglow light curve (https://www.swift.ac.uk/xrt_curves/01126853/ <https://www.swift.ac.uk/xrt_curves/01126853/>), rescaling the t-t0 with 
respect to the time of the GBM trigger, and find statistical evidence that a broken power-law decay provides a better fit with respect to a single 
power-law decay, with a break time at about 1 day. 

By performing a joint fit to the H, z and X-ray bands, with a broken power-law model we find the the overall dataset is best fit with a broken 
power-law with decay indices alpha1_X ~ 1.5, alpha2_X ~ 1.9, alpha1_NIR = alpha1_opt ~ 0.8, alpha2_NIR = alpha2_opt ~ 1.6 with a break 
time (forced to be equal in all light curves) t_b ~ 0.98 days. 

Under the assumption that such an achromatic break is the GRB jet-break, starting from the computed GRB Eiso (Frederiks et al., GCN Circ. 32668) 
we obtain a jet half-opening angle theta_jet ~ 3.5 deg and a beaming-corrected energy for the GRB of ~ 6e51 erg (using efficiency 0.2 and density
 n = 1 cm^(-3); Sari et al., 1999, ApJ, 519, L17; Rhoads, 1999, ApJ, 525, 737 ). 


