# GCN_circulars

GRB_name: GRB200917A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28450
SUBJECT: GRB 200917A: GROWTH-India Telescope optical upper limit.
DATE:    20/09/18 03:53:27 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), K. Sharma(IITB), U. Stanzin (IAO), V. Bhalerao(IITB), G.
C. Anupama(IIA), S. Barway(IIA), report on behalf of the GROWTH-India
collaboration:

We observed GRB 200917A reported by Swift-BAT (E. Sonbas et al., GCN 28435,
M.R. Goad et al., GCN 28436) with 0.7m GROWTH-India Telescope (GIT). The
field was observed in the SDSS râ€™ filter starting at 2020-09-17T14:15:12.96 UT
i.e. ~10.37 hrs after the event detection by Swift-BAT. We obtained 6
exposures of 300 sec each, at an airmass of ~2.5. We did not find any
source in the stacked image within the uncertainty region of 1.9 arcsec
around the Swift-XRT position of RA(J2000): 15h 42m 53.84s, Dec(J2000):
-04d 42' 02.1" (GCN  28436). We obtained an upper limit of r > 20.23
mag (5-sigma),
calibrated against PanSTARRs PS1 data release (Flewelling et al., 2018).

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 and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB200916B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28451
SUBJECT: GRB 200916B: AstroSat CZTI detection
DATE:    20/09/18 14:41:34 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: 

Analysis of AstroSat CZTI data showed detection of a short GRB 200916B, which was also detected by IPN ( Ridnaia A. et al., GCN #28440). 

The source was clearly detected in the 40-200 keV energy range. The light curve showed a single peak of emission peaking at 2020-09-16 15:41:29.437 UT. The measured peak count rate associated with the burst is 143 +/- 23 cts/s above the background in the combined data of four quadrants, with a total of 230 +/- 2 cts. The local mean background count rate was 422 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 1.7 s. 

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed a single peak of emission peaking at 2020-09-16 15:41:28.00 UT. The measured peak count rate is 378 +/- 46 cts/s above the background in the combined Veto data of four quadrants, with a total of 727 +/- 5 cts. The local mean background count rate was 1739 +/- 2 cts/s. We measure a T90 of 1.7 s from the cumulative Veto light curve. 

CZTI GRB detections are reported regularly on the payload site atâ€‹ http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project. 


GRB_name: GRB200919A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28454
SUBJECT: GRB 200919A: Swift detection of a burst
DATE:    20/09/19 02:00:19 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. N. Ukwatta (LANL), D. N. Burrows (PSU), V. D'Elia (SSDC),
S. Laha (GSFC/UMBC/CRESST), D. M. Palmer (LANL), B. Sbarufatti (PSU)
and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels
Swift Observatory Team:

At 01:52:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200919A (trigger=996503).  Swift did not slew due to an
observing constraint.  The BAT on-board calculated location is 
RA, Dec 168.916, +32.457 which is 
   RA(J2000) = 11h 15m 40s
   Dec(J2000) = +32d 27' 25"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single complex peak
structure with a duration of about 40 sec.  The peak count rate
was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 05:40 UT on 2020 October 10. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta 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: GRB200916B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28456
SUBJECT: GRB 200916B: MASTER optical observation
DATE:    20/09/19 12:27:13 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, A.Kuznetsov, K.Zhirkov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, A.Chasovnikov, V.Topolev, 
A.Pozdnyakov, D.Cheryasov(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),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov, Yu. Sergienko (Blagoveschensk Educational State University)


MASTER-SAAO robotic telescope
(Global MASTER-Net http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, 2010, 30L)
located in South Africa (South African Astronomical Observatory)
started inspect of short GRB200916B (Ridnaia et al. GCN 28440) errorbox 
85399s after notice time (2 days 6634s after trigger time) at 2020-09-18 17:32:03 UT,
with upper limit  to  19.4 mag.
The observations began at zenith distance = 45 deg. The sun altitude was -13.4 deg.
The galactic latitude b = -60 deg., longitude l = 98 deg.

Real time updated cover map:
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11529

We obtained following upper limits.

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
   179525 | 2020-09-18 17:32:03 |         MASTER-SAAO | (15h 02m 46.17s , -37d 57m 43.2s) |   C |   180 | 19.4 |
   180925 | 2020-09-18 17:55:23 |         MASTER-SAAO | (14h 49m 20.69s , -39d 56m 18.2s) |   C |   180 | 19.3 |
   181124 | 2020-09-18 17:58:43 |         MASTER-SAAO | (14h 49m 16.07s , -39d 57m 17.9s) |   C |   180 | 19.3 |
Filter C is a clear (unfiltred) band.

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


GRB_name: GRB200919B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28457
SUBJECT: GRB 200919B: Fermi GBM Final Real-time Localization
DATE:    20/09/19 13:49:21 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 13:38:51 UT on 19 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200919B (trigger 622215536.063538 / 200919569).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 55.5, Dec = 35.6 (J2000 degrees, equivalent to J2000 03h 42m, 35d 36'), with a statistical uncertainty of 8.9 degrees.

The angle from the Fermi LAT boresight is 105.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200919569/quicklook/glg_skymap_all_bn200919569.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200919569/quicklook/glg_healpix_all_bn200919569.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200919569/quicklook/glg_lc_medres34_bn200919569.gif


GRB_name: GRB200919A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28458
SUBJECT: GRB 200919A: Swift-BAT refined analysis
DATE:    20/09/19 17:27:57 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 200919A
(trigger #996503) (Ukwatta et al., GCN Circ. 28454).
The BAT ground-calculated position is
RA, Dec = 168.899, 32.456 deg which is
   RA(J2000)  =  11h 15m 35.7s
   Dec(J2000) = +32d 27' 21.8"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 62%.

The mask-weighted light curve shows several overlapping pulses
that start at ~T-60 s and end at ~T+25 s. The main peak
occurs at ~T+5 s. T90 (15-350 keV) is 76.0 +- 6.9 sec
(estimated error including systematics).

The time-averaged spectrum from T-61.47 to T+24.54 sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 2.13 +- 0.14.  The fluence in the 15-150 keV band
is 1.8 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured
from T+4.30 sec in the 15-150 keV band is 1.2 +- 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/996503/BA/


GRB_name: GRB200919B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28459
SUBJECT: Fermi GRB 200919B: Global MASTER-Net observations report 
DATE:    20/09/19 17:30:13 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

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




MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 200919B ( Fermi GBM team, GCN 28457) errorbox  11193 sec after notice time and 11243 sec after trigger time at 2020-09-19 16:46:14 UT, with upper limit up to  17.3 mag. Observations started at twilight.  The observations began at zenith distance = 79 deg. The sun  altitude  is -11.6 deg. 

The galactic latitude b = -15 deg., longitude l = 158 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1444610

We obtain a following upper limits.  

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

   11273 | 2020-09-19 16:46:14 |      MASTER-Tavrida | (02h 52m 32.33s , +40d 01m 18.7s) |   C |    60 | 16.2 |        
   11434 | 2020-09-19 16:48:55 |      MASTER-Tavrida | (02h 57m 52.35s , +42d 00m 59.1s) |   C |    60 | 16.3 |        
   11837 | 2020-09-19 16:55:37 |      MASTER-Tavrida | (02h 52m 28.23s , +40d 02m 15.8s) |   C |    60 | 17.0 |        
   11917 | 2020-09-19 16:56:58 |      MASTER-Tavrida | (02h 57m 53.34s , +42d 01m 29.4s) |   C |    60 | 16.8 |        
   12159 | 2020-09-19 17:01:00 |      MASTER-Tavrida | (02h 57m 49.58s , +38d 00m 39.2s) |   C |    60 | 16.9 |        
   12321 | 2020-09-19 17:03:41 |      MASTER-Tavrida | (03h 02m 58.94s , +40d 01m 29.9s) |   C |    60 | 17.2 |        
   12482 | 2020-09-19 17:06:22 |      MASTER-Tavrida | (02h 57m 49.81s , +38d 01m 47.5s) |   C |    60 | 17.0 |        
   12562 | 2020-09-19 17:07:43 |      MASTER-Tavrida | (03h 07m 57.80s , +38d 00m 41.9s) |   C |    60 | 16.8 |        
   12905 | 2020-09-19 17:13:25 |      MASTER-Tavrida | (03h 03m 02.43s , +40d 01m 29.2s) |   C |    60 | 17.3 |        
   12985 | 2020-09-19 17:14:46 |      MASTER-Tavrida | (03h 13m 21.88s , +40d 00m 43.2s) |   C |    60 | 17.1 |        
   13227 | 2020-09-19 17:18:47 |      MASTER-Tavrida | (03h 08m 01.60s , +38d 00m 30.1s) |   C |    60 | 17.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200919A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28460
SUBJECT: GRB 200919A: CrAO/ZTSh early optical upper limit
DATE:    20/09/19 21:12:19 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI),  V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on 
behalf of IKI-GRB-FuN:

We observed the  GRB 200919A (Ukwatta et al., GCN 28454)  with ZTSH 2.6m 
telescope of CrAO observatory starting on 2020-09-19 (UT) 02:26:25. We 
do not detect any new evident object in the BAT GRB 200919A localization 
field (Ukwatta et al., GCN 28454).
Preliminary photometry of the field is following
Date       UT start  t-T0    Filter Exp.   OT    Err. UL
                     (mid, days)     (s)
2020-09-19 02:26:25  0.02541 R      30*10  n/d   n/d 19.8

The photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id R2
1224-0243383 15.75
1224-0243414 15.12


GRB_name: GRB200919C
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28461
SUBJECT: GRB 200919C: Fermi GBM Final Real-time Localization
DATE:    20/09/19 23:18:39 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 23:08:22 UT on 19 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200919C (trigger 622249707.644918 / 200919964).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 273.4, Dec = -23.2 (J2000 degrees, equivalent to J2000 18h 13m, -23d 11'), with a statistical uncertainty of 1.2 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/2020/bn200919964/quicklook/glg_skymap_all_bn200919964.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200919964/quicklook/glg_healpix_all_bn200919964.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200919964/quicklook/glg_lc_medres34_bn200919964.gif


GRB_name: GRB200919C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28462
SUBJECT: Fermi GRB 200919C: Global MASTER-Net observations report 
DATE:    20/09/20 00:30:24 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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) started inspect of the Fermi GRB 200919C ( Fermi GBM team, GCN 28461) errorbox  92 sec after notice time and 120 sec after trigger time at 2020-09-19 23:10:23 UT, with upper limit up to  17.6 mag. Observations started at twilight.  The observations began at zenith distance =  9 deg. The sun  altitude  is -9.6 deg. 

MASTER-SAAO robotic telescope  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 200919C errorbox  119 sec after notice time and 147 sec after trigger time at 2020-09-19 23:10:50 UT, with upper limit up to  14.2 mag. The observations began at zenith distance = 80 deg. The sun  altitude  is -57.8 deg. 

The galactic latitude b = -3 deg., longitude l =  8 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1444890

We obtain a following upper limits.  

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

     131 | 2020-09-19 23:10:23 |         MASTER-OAFA | (18h 19m 08.51s , -22d 37m 56.3s) |   C |    20 | 15.9 |        
     162 | 2020-09-19 23:10:50 |         MASTER-SAAO | (18h 19m 36.27s , -22d 32m 15.4s) |   C |    30 | 12.7 |        
     175 | 2020-09-19 23:11:02 |         MASTER-OAFA | (18h 15m 37.21s , -23d 14m 33.1s) |   C |    30 | 16.2 |        
     220 | 2020-09-19 23:11:02 |         MASTER-OAFA | (18h 15m 37.22s , -23d 14m 33.0s) |   C |   120 | 16.7 |  Coadd 
     217 | 2020-09-19 23:11:39 |         MASTER-SAAO | (18h 19m 42.17s , -22d 33m 13.2s) |   C |    40 | 14.2 |        
     230 | 2020-09-19 23:11:52 |         MASTER-OAFA | (18h 15m 40.83s , -23d 12m 39.1s) |   C |    40 | 16.3 |        
     281 | 2020-09-19 23:12:38 |         MASTER-SAAO | (18h 19m 37.00s , -22d 34m 10.9s) |   C |    50 | 13.8 |        
     294 | 2020-09-19 23:12:51 |         MASTER-OAFA | (18h 15m 33.60s , -23d 13m 34.7s) |   C |    50 | 16.5 |        
     356 | 2020-09-19 23:13:48 |         MASTER-SAAO | (18h 19m 41.80s , -22d 33m 51.0s) |   C |    60 | 13.8 |        
     374 | 2020-09-19 23:14:01 |         MASTER-OAFA | (18h 15m 34.31s , -23d 12m 34.4s) |   C |    70 | 16.6 |        
     464 | 2020-09-19 23:14:01 |         MASTER-OAFA | (18h 15m 34.30s , -23d 12m 34.4s) |   C |   250 | 17.0 |  Coadd 
     445 | 2020-09-19 23:15:08 |         MASTER-SAAO | (18h 19m 38.75s , -22d 32m 04.7s) |   C |    80 | 12.7 |        
     469 | 2020-09-19 23:15:31 |         MASTER-OAFA | (18h 15m 40.04s , -23d 13m 34.7s) |   C |    80 | 16.8 |        
     555 | 2020-09-19 23:16:47 |         MASTER-SAAO | (18h 19m 38.69s , -22d 33m 57.1s) |   C |   100 | 13.6 |        
     578 | 2020-09-19 23:17:10 |         MASTER-OAFA | (18h 15m 33.16s , -23d 14m 34.6s) |   C |   100 | 16.9 |        
     685 | 2020-09-19 23:18:47 |         MASTER-SAAO | (18h 16m 01.39s , -23d 13m 46.8s) |   C |   120 | 12.1 |        
     712 | 2020-09-19 23:19:10 |         MASTER-OAFA | (18h 11m 58.22s , -23d 56m 21.3s) |   C |   130 | 17.3 |        
     882 | 2020-09-19 23:19:10 |         MASTER-OAFA | (18h 11m 58.22s , -23d 56m 21.3s) |   C |   470 | 17.5 |  Coadd 
     839 | 2020-09-19 23:21:06 |         MASTER-SAAO | (18h 15m 54.46s , -23d 14m 35.1s) |   C |   150 | 12.5 |        
     877 | 2020-09-19 23:21:39 |         MASTER-OAFA | (18h 11m 55.67s , -23d 54m 35.7s) |   C |   160 | 17.4 |        
    1024 | 2020-09-19 23:23:56 |         MASTER-SAAO | (18h 15m 53.68s , -23d 13m 25.4s) |   C |   180 | 12.3 |        
    1066 | 2020-09-19 23:24:39 |         MASTER-OAFA | (18h 11m 55.63s , -23d 56m 13.8s) |   C |   180 | 17.5 |        
    1266 | 2020-09-19 23:27:58 |         MASTER-OAFA | (18h 11m 58.50s , -23d 54m 40.9s) |   C |   180 | 17.6 |        
    1465 | 2020-09-19 23:31:18 |         MASTER-OAFA | (18h 11m 52.71s , -23d 55m 31.2s) |   C |   180 | 17.5 |        
    1665 | 2020-09-19 23:34:37 |         MASTER-OAFA | (18h 11m 51.61s , -23d 54m 31.9s) |   C |   180 | 17.2 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200920A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28463
SUBJECT: GRB 200920A: Fermi GBM Final Real-time Localization
DATE:    20/09/20 15:47:09 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 15:36:47 UT on 20 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200920A (trigger 622309012.161358 / 200920651).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 211.1, Dec = -24.3 (J2000 degrees, equivalent to J2000 14h 04m, -24d 18'), with a statistical uncertainty of 13.9 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/2020/bn200920651/quicklook/glg_skymap_all_bn200920651.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200920651/quicklook/glg_healpix_all_bn200920651.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200920651/quicklook/glg_lc_medres34_bn200920651.gif


GRB_name: GRB200131A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  26977
SUBJECT: GRB 200131A: Further RATIR Optical Observations
DATE:    20/02/03 19:22:08 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 200131A (Sbarufatti et al., GCN 26953) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2020/02 2.10 to 2020/02 2.17
UTC (27.70 to 29.45 hours after the BAT trigger), obtaining a total of
1.42 hours exposure in the r and i bands, and from 2020/02 3.10 to
2020/02 3.12 UTC (51.69 to 52.28 hours after the BAT trigger), obtaining
a total of 0.49 hours exposure in the r and i bands.

The optical transient (Lipunov et al., GCN Circ. 26954, Butler et al.,
GCN Circ. 26957, Strausbaugh et al., GCN Circ. 26959, Gokuldass et al.,
GCN Circ. 26960, Pozanenko et al., GCN Circ. 26964 & 26965) is detected
on 2020/02/02 with:

  r = 21.39 +/- 0.11
  i = 21.39 +/- 0.07

and on 2020/02/03 with:

  r = 22.26 +/- 0.29
  i = 22.45 +/- 0.35

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB200920B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28464
SUBJECT: GRB 200920B: AGILE/MCAL detection of a burst
DATE:    20/09/21 08:35:02 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

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

The AGILE Mini-CALorimeter (MCAL) detected the short GRB 200920B at T0 =
2020-09-20 19:56:59.52 +/- 0.01 s (UTC), detected also by Fermi/GBM
(trigger 622324624 / 200920651).

The event lasted about 0.42 s and released a total number of ~505 counts in
the detector (in the 0.4-100 MeV energy range), above an average background
rate of 540 Hz.

The time-integrated spectrum of the burst can be fitted in the energy range
0.4-5 MeV with a single power-law with ph.ind. = 2.41 -0.30/+0.37,
resulting in a reduced chi-squared of 1.14 (36 d.o.f.) and a fluence of
3.46e-7 ergs/cm^2 (90% confidence level), in the same energy range.

The MCAL light curve can be found at
http://www.agilescienceapp.it/notices/GRB200920B_069656_527716619.529166.png
.

The event is also clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 18-60 keV), MCAL (0.4-100 MeV), and AntiCoincidence (50-200
keV) detectors. Their light curves can be found at:
http://www.agilescienceapp.it/notices/GRB200920B_AGILE_RM.png .

The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress.
Automatic MCAL GRB alert Notice


GRB_name: GRB200914A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28466
SUBJECT: GRB 200914A: Swift-XRT further observations
DATE:    20/09/21 17:19:16 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

P. Dâ€™Avanzo (INAF-OAB), T. Sbarrato (INAF-OAB), M. G. Bernardini (INAF-OAB), 
A. Melandri  (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the 
Swift-XRT team:

Swift-XRT has performed further follow-up observations of the INTEGRAL-detected
burst GRB 200914A (Mereghetti et al. GCN Circ. 28419), collecting 5.7 ks of Photon 
Counting (PC) mode data between T0+325 ks and T0+395 ks. 

The only uncatalogued source in the field, Source 1 (Perri et al., GCN Circ. 28425), 
is not detected anymore down to a 3sigma count rate limit of 2.1e-3 ct s^-1. 
From a re-analysis of the first XRT observation, consisting in 1.2 ks of data collected between 
T+9.0 ks and T+10.2 ks, we measure a count rate of 6.6e-3 (+3.3e-3, -2.5e-3) ct s^-1. 

Although there is moderate evidence for fading between these two epochs, we cannot exclude 
that the observed X-ray emission is coming from the bright IR source reported in Perri et al. 
(GCN Circ. 28425), possibly unrelated to GRB 200914A. 


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


GRB_name: GRB200920B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28467
SUBJECT: IPN triangulation of GRB 200920B (short)
DATE:    20/09/21 20:34:34 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

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

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and A. Ursi, F. Verrecchia, M. Tavani, N. Parmiggiani, C. Pittori,
A. Bulgarelli, on behalf of the AGILE team, report:

The short-duration GRB 200920B
(AGILE/MCAL detection: Ursi et al., GCN Circ. 28464)
has been detected by Fermi (GBM trigger 622324624), Konus-Wind,
INTEGRAL (SPI-ACS), and AGILE (MCAL), so far,
at about 71815 s UT (19:56:55).

We have triangulated it to a Konus-GBM annulus centered at
RA(2000)=157.135 deg (10h 28m 32s)  Dec(2000)=+10.976 deg (+10d 58' 33"),
whose radius is 4.834 +/- 1.787 deg (3 sigma),
to a Konus-INTEGRAL annulus centered at
RA(2000)=154.111 deg (10h 16m 27s)  Dec(2000)=+8.715 deg (+8d 42' 54"),
whose radius is 7.120 +/- 1.815 deg (3 sigma), and
to a GBM-INTEGRAL annulus centered at
RA(2000)=77.242 deg (05h 08m 58s)  Dec(2000)=-35.743 deg (-35d 44' 36"),
whose radius is 90.000 +/- 4.602 deg (3 sigma).

The preliminary, 3 sigma error box is:
 ---------------------------------------------
  RA(2000), deg       Dec(2000), deg
 ---------------------------------------------
 Center:
  160.5209           +13.4321
 Corners:
  161.4146           +14.0653
  155.8758           +17.4839
  150.6190           +12.7611
  155.8316           +13.7440
  159.6319           +12.7958
  159.4728           +8.9807
  157.1525           +4.3546
  163.1097           +7.9563
 ---------------------------------------------
The error box area is 51.5 sq. deg, and its maximum
dimension is 13.2 deg (the minimum one is 2.1 deg).
The Sun distance was 123 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200920_T71814/IPN/

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


GRB_name: GRB200922A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28471
SUBJECT: GRB 200922A: Swift detection of a burst with possible optical counterpart
DATE:    20/09/22 12:26:24 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. J. Moss (GWU), E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC),
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), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report
on behalf of the Neil Gehrels Swift Observatory Team:

At 12:06:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200922A (trigger=997024).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 296.915, -55.204 which is 
   RA(J2000) = 19h 47m 40s
   Dec(J2000) = -55d 12' 12"
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 10 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 12:08:02.2 UT, 75.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 296.95425, -55.20245 which
is equivalent to:
   RA(J2000)  = 19h 47m 49.02s
   Dec(J2000) = -55d 12' 08.8"
with an uncertainty of 4.2 arcseconds (radius, 90% containment). This
location is 80 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 4.71
x 10^20 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 8.21e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 85 seconds after the BAT trigger. The 2.7'x2.7'
sub-image covers 100% of  the XRT error circle. There is a 14.4 mag
source at (296.95361,-55.20447)  8.3 arc seconds from the center of
the XRT error region. There is a  much weaker source at the same
position in the DSS. No  correction has been made for the expected
extinction corresponding to E(B-V) of  0.05. 

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: GRB200919C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28472
SUBJECT: GRB 200919C: Insight-HXMT/HE detection
DATE:    20/09/22 15:22:53 GMT
FROM:    Wangchen Xue at IHEP  <xuewc@ihep.ac.cn>

W. C. Xue, Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, 
C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, 
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, 
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-09-19T23:08:22.64 (T0), Insight-HXMT/HE detected 
GRB 200919C (trigger ID: HEB200919964) in a routine search of the data, 
which also triggered Fermi/GBM (Fermi GBM team, GCN #28461).

The Insight-HXMT/HE light curve mainly consists of multiple  
pulses with a duration (T90) of 58.43 s measured from T0+2.33 s. 
The 1-ms peak rate, measured from T0+50.10 s, is 1160 cnts/sec. 
The total counts from this burst is 17758 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB200919964_lc.jpg

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB200922A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28473
SUBJECT: GRB 200922A: Enhanced Swift-XRT position
DATE:    20/09/22 17:56:59 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 50 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 200922A, 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 = 296.95259, -55.20359 which is equivalent
to:

RA (J2000): 19h 47m 48.62s
Dec (J2000): -55d 12' 12.9"

with an uncertainty of 2.5 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: GRB200922B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28474
SUBJECT: GRB 200922B: Fermi GBM Final Real-time Localization
DATE:    20/09/22 18:14:41 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 18:04:24 UT on 22 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200922B (trigger 622490669.239676 / 200922753).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 136.2, Dec = 28.0 (J2000 degrees, equivalent to J2000 09h 04m, 28d 00'), with a statistical uncertainty of 7.4 degrees.

The angle from the Fermi LAT boresight is 40.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200922753/quicklook/glg_skymap_all_bn200922753.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200922753/quicklook/glg_healpix_all_bn200922753.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200922753/quicklook/glg_lc_medres34_bn200922753.gif


GRB_name: GRB200917A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28475
SUBJECT: GRB 200917A: Swift/UVOT Upper Limits
DATE:    20/09/22 20:13:27 GMT
FROM:    Kira Simpson at PSU  <kira.simpson1984@gmail.com>

GRB 200917A: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200917A
104 s after the BAT trigger (Sonbas et al., GCN Circ. 28435).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 28436)
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           104          254          147         >19.9
u_FC               262          512          246         >20.1
white              104         1708          412         >20.5
v                  592         1758          136         >18.9
b                  518         1684          117         >19.5
u                  262         1832          382         >20.2
w1                 641         1807          136         >18.7
m2                1762         1782           19         >18.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.19 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200922A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28476
SUBJECT: GRB 200922A: Swift-XRT refined Analysis
DATE:    20/09/22 20:52:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU),
D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB), T.
Sbarrato (INAF-OAB) and M.J. Moss report on behalf of the Swift-XRT
team:

We have analysed 6.8 ks of XRT data for GRB 200922A (Moss et al. GCN
Circ. 28471), from 81 s to 23.1 ks after the  BAT trigger. The data
comprise 123 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN Circ. 28473).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.148 (+0.026, -0.025).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.33 (+0.18, -0.17). The
best-fitting absorption column is  1.6 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 4.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.18 (+0.24, -0.23)
and a best-fitting absorption column of 2.4 (+0.9, -0.8) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.3 x 10^-11 (5.0 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.4 (+0.9, -0.8) x 10^21 cm^-2
Galactic foreground: 4.7 x 10^20 cm^-2
Excess significance: 4.3 sigma
Photon index:      2.18 (+0.24, -0.23)

If the light curve continues to decay with a power-law decay index of
1.148, the count rate at T+24 hours will be 4.8 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.6 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/00997024.

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


GRB_name: GRB200922A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28477
SUBJECT: Swift GRB 200922A: Global MASTER-Net observations report 
DATE:    20/09/22 22:36:19 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200922A ( M. J. Moss et al., GCN 28471) errorbox  37015 sec after notice time and 37039 sec after trigger time at 2020-09-22 22:24:05 UT, with upper limit up to  20.5 mag. The observations began at zenith distance = 48 deg. The sun  altitude  is -57.9 deg. 

The galactic latitude b = -30 deg., longitude l = 343 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1446564

We obtain a following upper limits.  

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

   37129 |         MASTER-SAAO |   C |   180 | 20.5 |        
   37129 |         MASTER-SAAO |   C |   180 | 20.4 |        
   37329 |         MASTER-SAAO |   C |   180 | 20.5 |        
   37329 |         MASTER-SAAO |   C |   180 | 20.4 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200922A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28478
SUBJECT: GRB 200922A: LCO observations 
DATE:    20/09/22 23:40:25 GMT
FROM:    Luca Izzo at DARK/NBI  <luca.izzo@gmail.com>

L. Izzo (DARK/NBI), D. B. Malesani (DTU Space) and D. A. Kann (HETH/IAA-CSIC) report:

We observed the field of GRB 200922A (Moss et al., GCN #28471) with the Sinistro instrument mounted on the 1-m telescope of the LCO network located at Siding Spring Observatory, Australia. Observations started on September 22 at 13:53:10 UT (1.77 hours after the GRB trigger). We obtained a series of 5x120s images in r and i filters each.

Within the UVOT-enhanced XRT position at RA (J2000) = 19:47:48.87 (296.95364), Dec. (J2000) = -55:12:15.9 (-55.20442) with an error of 1".5 (improved compared to the one reported in Osborne et al., GCN #28473) we clearly detect the source that had also been seen in the early UVOT observation (Moss et al., GCN #28471) at a white magnitude of 14.4.  In our stacked image we measure i = 17.31 +- 0.04 (AB mag), calibrated against nearby SkyMapper catalog stars. This value is brighter than the archival value i = 17.74 +- 0.01 mag from the SkyMapper Data Release 2 (Onken et al., 2019, PASA 36, 33).  Our result suggests variability compared to the historic value, and likely fading compared to the earlier UVOT observation. Similar fading is also measured versus archival DECam field images (i = 17.79 +- 0.02 mag, NOIRLab Prop. ID 2017A-0388; PI: A. Zenteno).

The coordinates of the source in our images are (J2000):

RA = 19:47:48.9285
Dec = -55:12:16.421

At this stage, it is unclear if this GRB was caused by the likely stellar source, or if it is a background GRB that happens to have occurred very close to a foreground object. Further observations are encouraged.

This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 730890.


GRB_name: GRB200922B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28479
SUBJECT: Fermi GRB 200922B: Global MASTER-Net observations report 
DATE:    20/09/23 02:45:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

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




MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 200922B ( Fermi GBM team, GCN 28474) errorbox  21798 sec after notice time and 21839 sec after trigger time at 2020-09-23 00:08:23 UT, with upper limit up to  18.4 mag. The observations began at zenith distance = 68 deg. The sun  altitude  is -34.4 deg. 

The galactic latitude b = 41 deg., longitude l = 199 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1446888

We obtain a following upper limits.  

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

   21870 | 2020-09-23 00:08:23 |      MASTER-Tavrida | (08h 36m 30.75s , +34d 09m 50.2s) |   C |    60 | 16.6 |        
   23399 | 2020-09-23 00:33:53 |      MASTER-Tavrida | (08h 36m 23.42s , +34d 10m 38.4s) |   C |    60 | 17.2 |        
   23479 | 2020-09-23 00:35:13 |      MASTER-Tavrida | (08h 46m 03.52s , +34d 11m 46.5s) |   C |    60 | 17.3 |        
   24445 | 2020-09-23 00:51:19 |      MASTER-Tavrida | (08h 46m 05.47s , +34d 11m 44.6s) |   C |    60 | 17.3 |        
   24928 | 2020-09-23 00:59:22 |      MASTER-Tavrida | (08h 22m 53.43s , +28d 10m 32.3s) |   C |    60 | 17.5 |        
   25090 | 2020-09-23 01:02:04 |      MASTER-Tavrida | (08h 31m 56.63s , +26d 09m 57.6s) |   C |    60 | 17.3 |        
   25412 | 2020-09-23 01:07:26 |      MASTER-Tavrida | (08h 33m 24.20s , +22d 09m 32.1s) |   C |    60 | 15.9 |        
   25574 | 2020-09-23 01:10:08 |      MASTER-Tavrida | (08h 41m 12.35s , +24d 11m 36.8s) |   C |    60 | 16.7 |        
   26138 | 2020-09-23 01:19:31 |      MASTER-Tavrida | (08h 32m 21.69s , +24d 10m 00.1s) |   C |    60 | 17.7 |        
   26218 | 2020-09-23 01:20:52 |      MASTER-Tavrida | (08h 22m 58.97s , +28d 11m 40.2s) |   C |    60 | 17.6 |        
   26299 | 2020-09-23 01:22:12 |      MASTER-Tavrida | (08h 31m 57.34s , +28d 10m 57.1s) |   C |    60 | 17.5 |        
   26540 | 2020-09-23 01:26:14 |      MASTER-Tavrida | (08h 31m 49.14s , +26d 09m 56.2s) |   C |    60 | 17.8 |        
   26620 | 2020-09-23 01:27:34 |      MASTER-Tavrida | (08h 40m 50.75s , +26d 10m 29.9s) |   C |    60 | 17.5 |        
   27023 | 2020-09-23 01:34:17 |      MASTER-Tavrida | (08h 33m 22.71s , +22d 11m 58.5s) |   C |    60 | 17.6 |        
   27103 | 2020-09-23 01:35:37 |      MASTER-Tavrida | (08h 42m 06.53s , +22d 11m 02.7s) |   C |    60 | 17.6 |        
   27345 | 2020-09-23 01:39:38 |      MASTER-Tavrida | (08h 41m 06.24s , +24d 11m 41.3s) |   C |    60 | 17.7 |        
   27425 | 2020-09-23 01:40:59 |      MASTER-Tavrida | (08h 49m 52.69s , +24d 10m 39.1s) |   C |    60 | 17.5 |        
   27747 | 2020-09-23 01:46:21 |      MASTER-Tavrida | (08h 32m 23.48s , +24d 11m 10.4s) |   C |    60 | 18.1 |        
   27828 | 2020-09-23 01:47:41 |      MASTER-Tavrida | (08h 31m 55.23s , +28d 10m 16.6s) |   C |    60 | 17.7 |        
   27989 | 2020-09-23 01:50:22 |      MASTER-Tavrida | (08h 40m 45.11s , +26d 12m 11.2s) |   C |    60 | 17.7 |        
   28557 | 2020-09-23 01:59:51 |      MASTER-Tavrida | (08h 41m 55.78s , +22d 12m 24.1s) |   C |    60 | 18.0 |        
   28718 | 2020-09-23 02:02:32 |      MASTER-Tavrida | (08h 49m 45.23s , +24d 10m 33.2s) |   C |    60 | 17.9 |        
   28799 | 2020-09-23 02:03:52 |      MASTER-Tavrida | (08h 32m 38.80s , +30d 12m 09.9s) |   C |    60 | 18.4 |        
   28960 | 2020-09-23 02:06:33 |      MASTER-Tavrida | (08h 40m 53.70s , +28d 12m 34.6s) |   C |    60 | 18.2 |        
   29281 | 2020-09-23 02:11:55 |      MASTER-Tavrida | (08h 32m 35.75s , +30d 11m 37.1s) |   C |    60 | 18.3 |        
   29362 | 2020-09-23 02:13:16 |      MASTER-Tavrida | (08h 41m 51.02s , +30d 12m 44.8s) |   C |    60 | 18.4 |        
   29603 | 2020-09-23 02:17:17 |      MASTER-Tavrida | (08h 41m 00.02s , +28d 11m 02.3s) |   C |    60 | 18.1 |        
   29684 | 2020-09-23 02:18:37 |      MASTER-Tavrida | (08h 50m 01.33s , +28d 12m 31.5s) |   C |    60 | 18.1 |        
   29845 | 2020-09-23 02:21:18 |      MASTER-Tavrida | (08h 34m 06.10s , +32d 12m 22.7s) |   C |    60 | 18.1 |        
   30246 | 2020-09-23 02:28:00 |      MASTER-Tavrida | (08h 41m 55.45s , +30d 11m 23.4s) |   C |    60 | 17.9 |        
   30407 | 2020-09-23 02:30:41 |      MASTER-Tavrida | (08h 50m 00.34s , +28d 11m 00.9s) |   C |    60 | 17.7 |        
   30488 | 2020-09-23 02:32:02 |      MASTER-Tavrida | (08h 34m 05.77s , +32d 12m 41.2s) |   C |    60 | 17.5 |        
   30971 | 2020-09-23 02:40:04 |      MASTER-Tavrida | (08h 49m 29.25s , +26d 13m 02.7s) |   C |    60 | 16.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200922A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28482
SUBJECT: GRB 200922A: Swift/UVOT Detection
DATE:    20/09/23 13:04:40 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>

M. H. Siegel (PSU) and M. J. Moss (GWU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200922A
86 s after the BAT trigger (Moss et al., GCN Circ. 28471).
We identify a fading source near the XRT position
(Osborne et al. GCN Circ. 28473) and also at the location of a weak source
in the DSS.  The source position is:

  RA(J2000)  = 19:47:48.76 = 296.95317
  DEC(J2000) = -55:12:16.5  = -55.20457

Which is 3.0 arc-second from the enhanced XRT position. 

Preliminary detections 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               86          236          147      14.37+/-0.02
white             4770         4970          196      17.51+/-0.04
white            28889        28909           19      18.62+/-0.20
v                 3745         3945          196      17.35+/-0.10
v                 9268        23149         1460      17.79+/-0.05
b                 4566         4765          196      17.95+/-0.07
b                27982        28889          881      18.49+/-0.05
u                 4360         4560          196      17.18+/-0.06
u                15921        16791          848      18.20+/-0.06
uvw1              4156         4355          196      17.23+/-0.10
uvw1             11089        15915          887      18.26+/-0.09
uvw1             50455        56029          225      18.97+/-0.27
uvm2              3950         4150          196      17.12+/-0.12
uvm2             10182        11081          885      18.19+/-0.10
uvm2             50396        55850          223      19.26+/-0.36
uvw2              3541         5089          307      17.14+/-0.09
uvw2             21653        22553          885      18.77+/-0.12
uvw2             50338        55672          223            >19.44

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200922A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28483
SUBJECT: Improved enhanced Swift-XRT position of GRB 200922A
DATE:    20/09/23 13:11:07 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), A. Dâ€™ai (INAF-IASFPA) and M. J. Moss (GWU)
report on behalf of the Swift-XRT team:

The enhanced-XRT position reported in GCN Circ. 28473 was a particularly poor
position and has been improved and shifted by the receipt of further data, as
noted by Izzo et al (GCN. Circ. 28478).

The best XRT position, available at
https://www.swift.ac.uk/xrt_positions/00997024/ is RA, Dec = 296.95364,
-55.20442 degrees which is equivalent to:

RA (J2000)  = 19h 47m 48.87s
Dec (J2000)  = -55d 12' 15.9â€

with an uncertainty of 1.5â€ (radius, 90% confidence). This position is
consistent with the source seen by UVOT and LCO (GCN Circs. 28471, 28478).

It is normal for the XRT position to evolve slightly as new data are received, with
the website always being the source of the most recent position. In the case of
this GRB, the first visibility window for Swift was very short, and the
satellite attitude appears to have been less stable than usual; this resulted in
the position in GCN 28473 being unusually inaccurate.

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


GRB_name: GRB200922A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28484
SUBJECT: GRB 200922A: Swift-BAT refined analysis
DATE:    20/09/23 14:47:47 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), M. J. Moss (GWU),
D. M. Palmer (LANL), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+871 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 200922A (trigger #997024)
(Moss et al., GCN Circ. 28471).  The BAT ground-calculated position is
RA, Dec = 296.954, -55.199 deg which is
   RA(J2000)  =  19h 47m 49.0s
   Dec(J2000) = -55d 11' 55.1"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 74%.

The mask-weighted light curve shows a single FRED-like pulse that
starts at ~T-2 s, peaks at ~T+0, and ends at ~T+16 s.
T90 (15-350 keV) is 10.30 +- 1.96 sec (estimated error including
systematics).

The time-averaged spectrum from T-1.91 to T+16.22 sec is best fit
by a power law with an exponential cutoff.  This fit gives a photon
index 1.43 +- 0.26, and Epeak of 39.3 +- 5.7 keV (chi squared 52.48
for 56 d.o.f.).  For this model the total fluence in the 15-150 keV
band is 2.8 +- 0.1 x 10^-6 erg/cm2 and the 1-sec peak flux measured
from T-0.46 sec in the 15-150 keV band is 11.4 +- 0.5 ph/cm2/sec.
A fit to a simple power law gives a photon index of 2.12 +- 0.06
(chi squared 76.50 for 57 d.o.f.). 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/997024/BA/


GRB_name: GRB200923A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28486
SUBJECT: GRB 200923A: Fermi GBM Final Real-time Localization
DATE:    20/09/23 18:08:09 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 17:57:43 UT on 23 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200923A (trigger 622576668.612544 / 200923748).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 126.3, Dec = -54.2 (J2000 degrees, equivalent to J2000 08h 25m, -54d 12'), with a statistical uncertainty of 11.9 degrees.

The angle from the Fermi LAT boresight is 18.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200923748/quicklook/glg_skymap_all_bn200923748.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200923748/quicklook/glg_healpix_all_bn200923748.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200923748/quicklook/glg_lc_medres34_bn200923748.gif


GRB_name: GRB200923A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28488
SUBJECT: Fermi GRB 200923A: Global MASTER-Net observations report 
DATE:    20/09/24 03:15:27 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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) started inspect of the Fermi GRB 200923A ( Fermi GBM team, GCN 28486) errorbox  19833 sec after notice time and 19860 sec after trigger time at 2020-09-23 23:28:43 UT, with upper limit up to  15.7 mag. Observations started at twilight.  The observations began at zenith distance = 81 deg. The sun  altitude  is -13.0 deg. 

The galactic latitude b = -9 deg., longitude l = 270 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1447664

We obtain a following upper limits.  

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

   19890 | 2020-09-23 23:28:43 |         MASTER-OAFA | (08h 21m 14.47s , -67d 19m 15.6s) |   C |    60 | 13.2 |        
   20169 | 2020-09-23 23:33:22 |         MASTER-OAFA | (09h 03m 53.41s , -67d 17m 40.0s) |   C |    60 | 14.5 |        
   20735 | 2020-09-23 23:42:48 |         MASTER-OAFA | (08h 42m 35.32s , -67d 19m 14.3s) |   C |    60 | 14.5 |        
   30169 | 2020-09-24 02:20:02 |         MASTER-OAFA | (07h 41m 44.86s , -66d 39m 20.2s) |   C |    60 | 15.7 |        
   30466 | 2020-09-24 02:24:59 |         MASTER-OAFA | (07h 08m 15.95s , -63d 18m 27.3s) |   C |    60 | 15.2 |        
   30832 | 2020-09-24 02:31:06 |         MASTER-OAFA | (07h 41m 46.93s , -65d 17m 08.2s) |   C |    60 | 14.3 |        
   30926 | 2020-09-24 02:32:39 |         MASTER-OAFA | (08h 01m 22.93s , -66d 39m 47.6s) |   C |    60 | 14.4 |        
   31019 | 2020-09-24 02:34:12 |         MASTER-OAFA | (07h 08m 22.08s , -63d 18m 00.7s) |   C |    60 | 14.1 |        
   31110 | 2020-09-24 02:35:43 |         MASTER-OAFA | (07h 26m 40.63s , -64d 38m 46.6s) |   C |    60 | 13.0 |        
   31766 | 2020-09-24 02:46:39 |         MASTER-OAFA | (08h 01m 25.36s , -65d 17m 24.8s) |   C |    60 | 14.0 |        
   31858 | 2020-09-24 02:48:12 |         MASTER-OAFA | (07h 26m 40.84s , -64d 38m 47.1s) |   C |    60 | 14.4 |        
   31954 | 2020-09-24 02:49:47 |         MASTER-OAFA | (06h 56m 51.23s , -61d 17m 48.9s) |   C |    60 | 13.6 |        
   32451 | 2020-09-24 02:58:04 |         MASTER-OAFA | (07h 44m 51.93s , -64d 39m 59.0s) |   C |    60 | 13.6 |        
   32544 | 2020-09-24 02:59:38 |         MASTER-OAFA | (07h 13m 52.80s , -61d 15m 49.9s) |   C |    60 | 13.4 |        
   32646 | 2020-09-24 03:01:19 |         MASTER-OAFA | (08h 21m 06.58s , -66d 37m 21.4s) |   C |    60 | 13.8 |        
   32742 | 2020-09-24 03:02:55 |         MASTER-OAFA | (06h 54m 21.05s , -57d 15m 33.1s) |   C |    60 | 12.9 |        
   32836 | 2020-09-24 03:04:29 |         MASTER-OAFA | (07h 44m 58.07s , -64d 38m 59.6s) |   C |    60 | 14.9 |        
   32934 | 2020-09-24 03:06:07 |         MASTER-OAFA | (08h 02m 56.16s , -63d 17m 01.2s) |   C |    60 | 13.7 |        
   33030 | 2020-09-24 03:07:43 |         MASTER-OAFA | (07h 14m 07.48s , -62d 40m 29.8s) |   C |    60 | 15.4 |        
   33122 | 2020-09-24 03:09:15 |         MASTER-OAFA | (07h 30m 53.96s , -61d 15m 34.1s) |   C |    60 | 14.3 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200924A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28489
SUBJECT: GRB 200924A: Fermi GBM Final Real-time Localization
DATE:    20/09/24 09:25:46 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 09:15:20 UT on 24 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200924A (trigger 622631725.82437 / 200924386).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 317.3, Dec = -56.4 (J2000 degrees, equivalent to J2000 21h 09m, -56d 23'), with a statistical uncertainty of 5.6 degrees.

The angle from the Fermi LAT boresight is 102.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200924386/quicklook/glg_skymap_all_bn200924386.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200924386/quicklook/glg_healpix_all_bn200924386.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200924386/quicklook/glg_lc_medres34_bn200924386.gif


GRB_name: GRB200922A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28490
SUBJECT: GRB 200922A: Insight-HXMT/HE detection
DATE:    20/09/24 11:02:22 GMT
FROM:    YaoGuang Zheng at IHEP  <zhengyg@ihep.ac.cn>

Y. Q. Zhang, Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, 
C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, 
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, 
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-09-22T12:06:46.00 (T0), Insight-HXMT/HE detected 
GRB 200922A (trigger ID: HEB200922504) in a routine search of the data, 
which also triggered Swift/BAT (Moss et al., GCN #28471).

The Insight-HXMT/HE light curve mainly consists of single  
pulses with a duration (T90) of 1.87 s measured from T0+0.04 s. 
The 1-ms peak rate, measured from T0+0.18 s, is 629 cnts/sec. 
The total counts from this burst is 742 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB200922504_lc.jpg

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB200922A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28492
SUBJECT: GRB 200922A: chance superposition between optical afterglow and archival star
DATE:    20/09/24 21:15:28 GMT
FROM:    Daniele B Malesani at DTU Space  <malesani@space.dtu.dk>

D. B. Malesani (DTU Space), L. Izzo (DARK/NBI), D. A. Kann (HETH, 
IAA/CSIC), A. de Ugarte Postigo (HETH, IAA/CSIC), A. J. Levan (Radboud 
Univ.), D. Xu (NAOC), P. D'Avanzo (INAF/OABr), and A. Rossi (INAF/OAS) 
report on behalf of the Stargate collaboration:

For the recent GRB 200922A, several authors have noted the presence of a 
bright optical afterglow, initially detected by UVOT onboard the Neil 
Gehrels Swift observatory (Moss et al., GCN 28471; Izzo et al., GCN 
28478; Siegel & Moss, GCN 28482), superimposed on a point-like object, 
seen e.g. in the DSS, DECam, and SkyMapper surveys.

We retrieved the white-band UVOT images (Siegel & Moss, GCN 28482). We 
focused on the initial image (344 s exposure starting at 12:08:32 UT on 
Sep 22) and on the image taken roughly one day after (274 s exposure 
starting at 10:05:38 UT on Sep 23). We also retrieved for comparison the 
archival DECam i-band images of the same region (from 2017 August).

We remark that the position of the UVOT object is entirely consistent 
with the latest XRT position of the afterglow (Evans et al., GCN 28483; 
see also https://www.swift.ac.uk/xrt_positions/), strengthening the 
association between the optical transient and GRB 200922A.

We then cross-matched the astrometry between the UVOT and the archival 
DECam images. The scatter in the astrometric solution, computed on stars 
of brightness similar to the UVOT afterglow, is 0.06 and 0.10 arcsec for 
the initial and late exposure, respectively.

In the initial UVOT image, we measure an offset of 0.62" compared to the 
object seen in the archival data. While small, this offset is 
significant. The same comparison carried out in the late time image, 
however, returns no measurable offset to within the errors. 
Independently, we also checked that the proper motion of the star 
(catalogued in the Gaia DR2; Brown et al. 2018, A&A, 616, A1) is too 
small to play any effect in producing the offset.

We thus conclude that this is a rare case of near-perfect chance 
superposition between a background afterglow and a bright foreground 
star. In the initial UVOT image, the light was dominated by the 
afterglow (thus yielding the offset in the position), which subsequently 
faded to a level fainter than the foreground star. The light curve of 
the X-ray afterglow (D'Ai et al., GCN 28476) is also consistent with 
this interpretation, as it shows the typical behaviour of a cosmological 
GRB.


A spectrum of the optical transient was taken using the ESO VLT1 UT1 
(Antu) equipped with the FORS2 instrument. Observations were carried out 
using the grisms 300V and 300I (900 s exposure each), covering the 
wavelength range 3500-9200 AA, and started on 2020 Sep 22.997 UT (11.8 
hr after the trigger). In the acquisition image, using (old) archival 
zeropoints, we measure V = 18.0 (Vega). This value is roughly consistent 
with the archival values of the star (for example the Gaia catalog gives 
G = 17.85), and indicates only little contribution from the afterglow at 
the epoch of our spectrum (at least in the V band).

The spectrum we observe is consistent with the one of a G-type star. 
Absorption features are observed at z = 0 from Ca H and K, Mg I, Na I D, 
Hdelta, Hgamma, Hbeta, and Halpha. The ordinary type of the star 
supports the lack of a connection with the GRB. A search was conducted 
for potential emission lines from the background GRB host galaxy, but 
the intense and spatially-variable glare from the star does not allow us 
to place quantitative limits. We are thus unfortunately unable to 
provide constraints on the GRB redshift.


We welcome the reopening of the ESO observatory at Paranal, even if at 
reduced capacity. We thank the ESO staff for carrying out our 
observations, in particular Steffen Mieske, Claudia Cid, and Romain 
Thomas, as well as and the entire support team on- and off-site.


GRB_name: GRB200924B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28493
SUBJECT: GRB 200924B: Fermi GBM Final Localization
DATE:    20/09/24 22:43:12 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 05:38:29 UT on 24 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200924B (trigger 622618714 / 200924235).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 319.4, Dec = 6.5 (J2000 degrees, equivalent to J2000 21h 18m, +6d 28'), with a statistical uncertainty of 3.8 degrees.

The angle from the Fermi LAT boresight is 71.2 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200924235/quicklook/glg_skymap_all_bn200924235.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200924235/quicklook/glg_healpix_all_bn200924235.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200924235/quicklook/glg_lc_medres34_bn200924235.gif


GRB_name: GRB200924A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28494
SUBJECT: Fermi GRB 200924A: Global MASTER-Net observations report 
DATE:    20/09/25 02:30:12 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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) started inspect of the Fermi GRB 200924A ( Fermi GBM team, GCN 28489) errorbox  60129 sec after notice time and 60192 sec after trigger time at 2020-09-25 01:58:33 UT, with upper limit up to  15.3 mag. The observations began at zenith distance = 27 deg. The sun  altitude  is -42.6 deg. 

The galactic latitude b = -42 deg., longitude l = 340 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1448070

We obtain a following upper limits.  

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

   60223 | 2020-09-25 01:58:33 |         MASTER-OAFA | (20h 49m 51.22s , -56d 45m 39.8s) |   C |    60 | 14.1 |        
   60302 | 2020-09-25 01:59:52 |         MASTER-OAFA | (20h 58m 38.41s , -58d 46m 15.3s) |   C |    60 | 14.4 |        
   60382 | 2020-09-25 02:01:12 |         MASTER-OAFA | (21h 18m 29.02s , -56d 46m 11.2s) |   C |    60 | 14.7 |        
   60461 | 2020-09-25 02:02:32 |         MASTER-OAFA | (21h 10m 38.64s , -54d 48m 00.6s) |   C |    60 | 14.4 |        
   60541 | 2020-09-25 02:03:51 |         MASTER-OAFA | (20h 49m 54.34s , -56d 47m 10.7s) |   C |    60 | 14.0 |        
   60620 | 2020-09-25 02:05:11 |         MASTER-OAFA | (21h 04m 11.26s , -56d 45m 59.3s) |   C |    60 | 14.3 |        
   60700 | 2020-09-25 02:06:30 |         MASTER-OAFA | (20h 58m 35.48s , -58d 47m 45.6s) |   C |    60 | 14.2 |        
   60779 | 2020-09-25 02:07:50 |         MASTER-OAFA | (21h 13m 45.91s , -58d 46m 14.1s) |   C |    60 | 14.4 |        
   60859 | 2020-09-25 02:09:09 |         MASTER-OAFA | (21h 18m 29.63s , -56d 47m 10.6s) |   C |    60 | 14.5 |        
   60938 | 2020-09-25 02:10:29 |         MASTER-OAFA | (21h 32m 50.07s , -56d 46m 25.7s) |   C |    60 | 14.9 |        
   61018 | 2020-09-25 02:11:48 |         MASTER-OAFA | (20h 43m 22.03s , -54d 47m 26.8s) |   C |    60 | 14.1 |        
   61098 | 2020-09-25 02:13:08 |         MASTER-OAFA | (21h 09m 59.77s , -60d 46m 15.1s) |   C |    60 | 14.4 |        
   61177 | 2020-09-25 02:14:28 |         MASTER-OAFA | (21h 10m 42.46s , -54d 47m 36.9s) |   C |    60 | 14.5 |        
   61257 | 2020-09-25 02:15:47 |         MASTER-OAFA | (21h 24m 24.41s , -54d 46m 37.7s) |   C |    60 | 14.9 |        
   61337 | 2020-09-25 02:17:07 |         MASTER-OAFA | (21h 04m 07.90s , -56d 46m 53.8s) |   C |    60 | 14.8 |        
   61416 | 2020-09-25 02:18:27 |         MASTER-OAFA | (21h 13m 40.79s , -58d 46m 06.5s) |   C |    60 | 15.3 |        
   61496 | 2020-09-25 02:19:46 |         MASTER-OAFA | (21h 32m 54.91s , -56d 47m 24.9s) |   C |    60 | 15.0 |        
   61775 | 2020-09-25 02:24:25 |         MASTER-OAFA | (20h 43m 28.21s , -54d 47m 10.1s) |   C |    60 | 14.2 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200914A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28495
SUBJECT: Konus-Wind observation of GRB 200914A
DATE:    20/09/25 14:29:03 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

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

The long-duration, hard-spectrum GRB 200914A
(Integral detection: Mereghetti et al., GCN 28419;
Fermi GBM observation: Dunwoody et al., GCN 28424;
AGILE detection: Ursi et al., GCN 28426)
triggered Konus-Wind at T0=46113.769 s UT (12:48:33.769).

The burst light curve shows a single pulse
which starts at ~T0-2.4 s and has a total duration of~38.0 s
The emission is seen up to ~2 MeV.

As observed by Konus-Wind, the burst
had a fluence of 4.26(-0.96,+1.08)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.306 s,
of 8.12(-2.44,+2.55)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.35(-0.34,+0.50),
the high energy photon index beta = -2.11(-0.70,+0.28),
the peak energy Ep = 461(-128,+201) keV,
chi2 = 93/97 dof.

The spectrum near the peak count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 1.6 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.58(-0.16,+0.19),
and Ep = 935(-170,+228) keV (chi2 = 86/98 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.51 (chi2 = 86/97 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200914_T46113/

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


GRB_name: GRB200925A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28496
SUBJECT: GRB 200925A: Fermi GBM Final Real-time Localization
DATE:    20/09/25 14:48:23 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 14:38:02 UT on 25 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200925A (trigger 622737487.659784 / 200925610).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 94.8, Dec = 32.0 (J2000 degrees, equivalent to J2000 06h 19m, 32d 00'), with a statistical uncertainty of 7.2 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/2020/bn200925610/quicklook/glg_skymap_all_bn200925610.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200925610/quicklook/glg_healpix_all_bn200925610.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200925610/quicklook/glg_lc_medres34_bn200925610.gif


GRB_name: GRB200925A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28497
SUBJECT: Fermi GRB 200925A: Global MASTER-Net observations report 
DATE:    20/09/25 16:15:19 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200925A ( Fermi GBM team, GCN 28496) errorbox  108 sec after notice time and 146 sec after trigger time at 2020-09-25 14:40:29 UT, with upper limit up to  18.2 mag. The observations began at zenith distance = 80 deg. The sun  altitude  is -32.2 deg. 

The galactic latitude b =  8 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=1448925

We obtain a following upper limits.  

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

     162 | 2020-09-25 14:40:29 |        MASTER-Tunka | (05h 49m 18.34s , +33d 03m 21.2s) |  P| |    30 | 15.6 |        
     216 | 2020-09-25 14:41:19 |        MASTER-Tunka | (05h 49m 25.59s , +33d 02m 22.8s) |  P| |    40 | 15.8 |        
     281 | 2020-09-25 14:42:18 |        MASTER-Tunka | (05h 49m 18.49s , +33d 01m 25.3s) |  P| |    50 | 16.0 |        
     356 | 2020-09-25 14:43:28 |        MASTER-Tunka | (05h 49m 24.92s , +33d 01m 42.2s) |  P| |    60 | 16.1 |        
     625 | 2020-09-25 14:47:57 |        MASTER-Tunka | (05h 41m 20.99s , +33d 40m 09.3s) |   C |    60 | 17.2 |        
     704 | 2020-09-25 14:49:16 |        MASTER-Tunka | (05h 49m 54.30s , +35d 40m 14.4s) |   C |    60 | 17.6 |        
     944 | 2020-09-25 14:53:17 |        MASTER-Tunka | (06h 00m 43.95s , +33d 40m 25.8s) |   C |    60 | 17.5 |        
    1266 | 2020-09-25 14:58:38 |        MASTER-Tunka | (05h 40m 01.57s , +35d 39m 22.7s) |   C |    60 | 17.8 |        
    1427 | 2020-09-25 15:01:19 |        MASTER-Tunka | (05h 49m 05.70s , +37d 40m 29.4s) |   C |    60 | 17.8 |        
    1589 | 2020-09-25 15:04:01 |        MASTER-Tunka | (05h 52m 36.69s , +31d 39m 53.6s) |   C |    60 | 17.0 |        
    1668 | 2020-09-25 15:05:21 |        MASTER-Tunka | (05h 45m 13.96s , +29d 40m 30.4s) |   C |    60 | 17.2 |        
    1831 | 2020-09-25 15:08:03 |        MASTER-Tunka | (05h 40m 02.08s , +35d 40m 32.1s) |   C |    60 | 17.9 |        
    1910 | 2020-09-25 15:09:22 |        MASTER-Tunka | (05h 49m 06.27s , +37d 39m 39.3s) |   C |    60 | 17.7 |        
    2073 | 2020-09-25 15:12:06 |        MASTER-Tunka | (05h 59m 14.54s , +37d 40m 05.8s) |   C |    60 | 17.9 |        
    2238 | 2020-09-25 15:14:50 |        MASTER-Tunka | (06h 09m 35.88s , +35d 40m 57.4s) |   C |    60 | 17.8 |        
    2401 | 2020-09-25 15:17:33 |        MASTER-Tunka | (05h 59m 12.36s , +37d 40m 10.1s) |   C |    60 | 18.0 |        
    2481 | 2020-09-25 15:18:53 |        MASTER-Tunka | (06h 09m 24.29s , +37d 41m 53.7s) |   C |    60 | 17.9 |        
    2565 | 2020-09-25 15:20:17 |        MASTER-Tunka | (06h 11m 28.89s , +31d 41m 50.1s) |   C |    60 | 17.4 |        
    2724 | 2020-09-25 15:22:56 |        MASTER-Tunka | (06h 03m 48.95s , +29d 41m 01.2s) |   C |    60 | 16.8 |        
    2803 | 2020-09-25 15:24:15 |        MASTER-Tunka | (06h 09m 18.37s , +37d 40m 08.5s) |   C |    60 | 17.9 |        
    3047 | 2020-09-25 15:28:19 |        MASTER-Tunka | (05h 56m 50.08s , +27d 40m 30.9s) |   C |    60 | 17.1 |        
    3126 | 2020-09-25 15:29:39 |        MASTER-Tunka | (05h 59m 04.82s , +39d 41m 53.6s) |   C |    60 | 18.2 |        
    3368 | 2020-09-25 15:33:40 |        MASTER-Tunka | (06h 20m 00.76s , +33d 40m 39.0s) |   C |    60 | 17.7 |        
    3447 | 2020-09-25 15:34:59 |        MASTER-Tunka | (05h 59m 07.43s , +39d 42m 15.0s) |   C |    60 | 18.2 |        
    5109 | 2020-09-25 16:02:41 |        MASTER-Tunka | (06h 09m 35.35s , +39d 41m 25.8s) |   C |    60 | 15.3 |        
    5191 | 2020-09-25 16:04:03 |        MASTER-Tunka | (06h 19m 31.73s , +37d 41m 19.3s) |   C |    60 | 13.9 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200925B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28499
SUBJECT: GRB 200925B: Swift detection of a burst
DATE:    20/09/25 22:00:50 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. B. Cenko (GSFC), C. Gronwall (PSU), J.D. Gropp (PSU),
N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and A. Tohuvavohu (U Toronto) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 21:50:37 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200925B (trigger=997453).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 246.851, +78.394 which is 
   RA(J2000) = 16h 27m 24s
   Dec(J2000) = +78d 23' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 40 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 21:51:55.3 UT, 78.4 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 246.78990, 78.39033 which is equivalent
to:
   RA(J2000)  = 16h 27m 09.58s
   Dec(J2000) = +78d 23' 25.2"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 46 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 4.59
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 81 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
0.04. 

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: GRB200925B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28500
SUBJECT: GRB 200925B: Prompt enhanced Swift-XRT position
DATE:    20/09/25 23:04:05 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 200925B, we find an
enhanced XRT position of the afterglow: RA, Dec: 246.7868, 78.3904
which is equivalent to:
   RA (J2000)  = 16 27 08.83
   Dec (J2000) = +78 23 25.5
with an uncertainty of 2.0 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/997453.

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: GRB200925B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28501
SUBJECT: GRB 200925B: OSN Afterglow Candidate Discovery
DATE:    20/09/25 23:14:27 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D. A. Kann, C. C. Thoene,
M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), and F. Aceituno 
(IAA-CSIC) report:

We observed the location of the Swift GRB 200925B (Cenko et al., GCN 
#28499) with the 1.5m telescope of the Observatorio Sierra Nevada, in 
Granada, Spain. We obtained a 300 s image each in the BVRc bands and 
multiple 100 s images in Ic, beginning 2020-09-25 22:27:07 UT.

We detect a source in all filters at

RA (J2000) = 16:27:08.50
Dec. (J2000) = +78:23:24.9

with an error of 0".5, within the UVOT-enhanced XRT position (Evans, GCN 
#28500). We note this source is also clearly detected in the initial 
Swift UVOT white finding chart, at a significantly brighter magnitude 
relative to the nearby field star.

This strongly suggests the source is fading and is therefore the 
afterglow of GRB 200925B.

At 0.034294 days after the GRB, we measure r' = 19.46 +/- 0.1 (AB 
magnitude) vs. nearby SDSS field stars.

[GCN OPS NOTE: Per the author's request: in the Title the "25A" was changed to "25B",
the affiliation of A. de Ugarte Postigo is "*-CSIC" not "*-CSIS",
"Thoene" not "Thone", and in the first sentence, the "200906A" should be "200925B".]


GRB_name: GRB200925B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28502
SUBJECT: Swift GRB 200925B: Global MASTER-Net OT detection
DATE:    20/09/26 00:05:19 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, P.Balanutsa, 
A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, 
D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

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),

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

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

MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, 
vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station)
was pointed to the Swift GRB200925A (trigger No 997453,16h 27m 24.24s , +78d 23m 38.4s, R=0.05) errorbox
14 sec after notice time and 58 sec after trigger time at 2020-09-25 21:51:35 UT,
  with upper limit up to  18.4 mag. The observations began at zenith distance = 53 deg. The sun  altitude  is -47.0 deg.

On our 4-th (40s exposure)  set , obtained 229 sec after tigger time at 2020-09-25 21:54:16 UT, we found an optical transient within Swift error-box (ra=246.851 dec=+78.394 r=0.05).


  T-Tmid      Date      Time       Expt.        Ra                Dec          Mag
---------|---------------------|-------|-----------------|-----------------|-----
      229   2020-09-25 21:54:16      40   (246.7866 d, +78.3896 d)   17.9

The OT position in within enhanced XRT position (GCN 28500) and is coincident with OSN afterglow candidate position (A. de Ugarte Postigo et al, GCN 28501)

The 5-sigma upper limit has been about  18.4 mag
The message may be cited.


GRB_name: GRB200925B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28503
SUBJECT: GRB 200925B: Enhanced Swift-XRT position
DATE:    20/09/26 04:08:17 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 1704 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 200925B, 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 = 246.78522, +78.39052 which is equivalent
to:

RA (J2000): 16h 27m 8.45s
Dec (J2000): +78d 23' 25.9"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB200922A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28505
SUBJECT: GRB 200922A: Chilescope optical observations
DATE:    20/09/26 16:18:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), S. Belkin (IKI), A. Volnova (IKI), P. Minaev (IKI), 
N. Pankov (HSE)  report on behalf GRB IKI FuN collaboration:

We observed the field of GRB 200922A (Moss et al., GCN 28471) with 
RC-1000 Chilescope observatory  in r'-filter starting on 2020-09-22 (UT) 
23:25:05. In a single obtained image of 1200 s exposure we cannot 
resolve the OT reported earlier (Moss et al., GCN 28471; Izzo et al., 
GCN 28478; Siegel  et al., GCN 28482; Malesani et al., GCN 28492). 
Instead we subtract the flux of nearby star from SkyMapper DR1.1 from 
the (nearby star + OT) photometry.
Preliminary photometry of the OT after the above-mentioned procedure is 
following.

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

2020-09-22 23:25:05  0.478   r'     1200  18.92  0.05  20.7

The photometry is based on nearby SkyMapper DR1.1  stars.


GRB_name: GRB200925B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28506
SUBJECT: GRB 200925B: Swift-BAT refined analysis
DATE:    20/09/26 18:03:43 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 200925B (trigger #997453)
(Cenko, et al., GCN Circ. 28499).  The BAT ground-calculated position is
RA, Dec = 246.892, 78.393 deg which is 
  RA(J2000)  =  16h 27m 34.1s 
  Dec(J2000) = +78d 23' 33.5" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.

The mask-weighted light curve shows two peaks, the first beginning ~T-2 sec,
peaking at T+5 sec, and decaying by T+12 sec.  The second, weaker, peak runs
from T+16 to T+22 sec.  T90 (15-350 keV) is 18.25 +- 0.97 sec (estimated error 
including systematics).

The time-averaged spectrum from T+0.20 to T+19.59 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.01 +- 0.14.  The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+4.38 sec in the 15-150 keV band
is 3.0 +- 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/997453/BA/


GRB_name: GRB200925B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28507
SUBJECT: GRB 200925B: Swift/UVOT Detection
DATE:    20/09/26 20:14:25 GMT
FROM:    Samantha Oates at MSSL  <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U.Birmingham) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200925B
82 s after the BAT trigger (Cenko et al., GCN Circ. 28499).
A source consistent with the XRT position (Beardmore et al. GCN Circ. 28503)
and the optical position reported by the OSN
(de Ugarte Postigo et al., GCN Circ. 28501) and MASTER
(Lipunov et al., GCN Circ. 28502) is detected in the initial UVOT exposures.

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

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

white (FC)      82          232           147        19.80 +/- 0.20
white           574         1714          264        20.77 +/- 0.37
v               623         1763          136        >18.9
b               549         1689          117        >19.6
u (FC)          294         544           246        >19.7
u               294         1663          343        >19.9
w1              672         1813          136        >19.0
m2              1249        1441           39        >17.7
w2              599         1739          117        >18.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200925B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28508
SUBJECT: GRB 200925B: Swift-XRT refined Analysis
DATE:    20/09/26 22:00:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U.
Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo
(INAF-OAB) and S.B. Cenko report on behalf of the Swift-XRT team:

We have analysed 5.1 ks of XRT data for GRB 200925B (Cenko et al. GCN
Circ. 28499), from 87 s to 47.2 ks after the  BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Beardmore et al. (GCN Circ. 28500). The
late-time light curve (from T0+29.2 ks) is consistent with a constant
source of mean count rate 1.3e-01 ct/sec. A power-law fit gives an
index of 1.0 (+/-1.2).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.12 (+0.19, -0.18). The
best-fitting absorption column is  7.5 (+4.4, -2.9) x 10^20 cm^-2,
consistent with the Galactic value of 4.6 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 3.1 x 10^-11 (3.8 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.5 (+4.4, -2.9) x 10^20 cm^-2
Galactic foreground: 4.6 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.12 (+0.19, -0.18)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00997453.

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


GRB_name: GRB200925B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28511
SUBJECT: GRB 200925B NUTTelA-TAO / BSTI Early Measurements (Preliminary)
DATE:    20/09/27 05:14:22 GMT
FROM:    Bruce Grossan at LBNL/UCB SSL  <Bruce_Grossan@lbl.gov>

B. Grossan (UCB, NU) , Z. Maksut (NU), A. Kim (NU), M. Krugov (FAI), G. F. Smoot (HKUST, UCB, NU), E. Linder (UCB, NU), report on behalf of the Energetic Cosmos Laboratory:

The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) pointed at GRB200925B on receipt of an automated GCN / BAT position alert. We report measurements made with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32,14) instrument  ***during commissioning phase*** and we note cautions with these measurements below.

Calibration with bright Pan-STARRS catalog I stars on our images, for our standard SDSS filters and 45 s co-added images yields, *without color corrections*, the following photometric values for the OT consistent with the position given in Evans et al. (GCN 28503): 


# tc-t0(s) g'(mag)     r'(mag)     i'(mag)
-- --------- -----------   -----------  ------------
1 67.5    UL18.27     UL18.07 UL17.32
2      136.5    UL18.15      18.62      17.94** 
3      181.5    UL18.21      17.99      17.47
4      226.5    UL18.25      18.09      17.63
5      271.5    UL18.27      18.17      17.48
6      316.5    UL18.31      18.26      17.70
7      361.5    UL18.14      18.60      17.83
8      406.5    UL18.17      18.55      17.87*

UL = 5 sigma upper limit
** = very large certainty, close to limit ; poor by-eye confirmation and aperture centering
* = large uncertainty ; poor by-eye confirmation and aperture centering
Other uncertainties are estimated at ~ 0.1 mag
tc-t0 = trigger time minus image center time.

The measurements suggest that the early emission peaked ~180 s after trigger.

We caution the reader that the BSTI instrument is in commissioning phase, with known imperfections, and we have not extensively tested our results, e.g. against other simultaneous measurements, or near our detection limits. Please also note that the times are approximate. We anticipate additional analysis in 15-30 days posted at http://ecl.nu.edu.kz/gamma-ray-burst/grb200925b. Some earlier images may have usable data. 

----------------------------------
UCB = University of California, Berkeley, USA
NU = Nazarbayev University, Nur-Sultan, Kazakhstan
HKUST = Hong Kong University of Science and Technology
FAI = Fesenkov Astrophysical Institute, Kazakhstan 

The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.


GRB_name: GRB200925B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28512
SUBJECT: GRB 200925B: Swift-XRT refined analysis update
DATE:    20/09/27 11:32:20 GMT
FROM:    Andy Beardmore at U Leicester  <ab271@leicester.ac.uk>

A.P. Beardmore (U. Leicester) and S. B. Cenko (GSFC) report on
behalf of the Swift-XRT team:

An additional 4.9 ks of Swift-XRT Photon Counting mode data have
been collected on GRB 200925B (Cenko et al.  GCN Circ. 28499,
Sbarufatti et al. GCN Circ. 28508), bringing the total XRT
exposure to 10 ks, from 87 s to 86.3 ks after the BAT trigger.
The late time X-ray light curve from T0+29.2 ks to 86.3 ks
is now decaying with a power-law decay slope of 1.1 +/- 0.4.

If the light curve continues to decay at the same rate than
the predicted count rate at T0+3 days will be 3.4e-03 count/sec,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 
1.05 x 10^-13 (1.28 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/00997453.

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


GRB_name: GRB200920B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28514
SUBJECT: Konus-Wind detection of GRB 200920B
DATE:    20/09/27 19:50:30 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

The short-duration GRB 200920B
(AGILE/MCAL detection: Ursi et al., GCN Circ. 28464;
IPN triangulation: Ridnaia et al., GCN Circ. 28467)
triggered Konus-Wind at T0=71814.617 s UT (19:56:54.617).

The burst light curve shows a multi-peaked structure
which started at ~T0-0.368 s and had a total duration of ~0.37 s.

The K-W light curve of this burst is available at
http://www.ioffe.ru/LEA/GRBs/GRB200920_T71814/

As observed by Konus-Wind, the burst had a fluence of
3.12(-0.61,+0.94)x10^-6 erg/cm2 and a 16-ms peak flux,
measured from ~T0-0.260 s, of 1.74(-0.52,+0.65)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the bulk of the burst emission was detected before
the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modelling the K-W 3-channel spectrum of the burst
(measured from T0-0.368 s to T0)
by the cutoff power law yields the following model parameters:
the photon index alpha = 0.15(-0.51,+0.95),
and the peak energy Ep = 935(-241,+401) keV.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB200928A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28518
SUBJECT: GRB 200928A: Fermi GBM Final Localization
DATE:    20/09/28 10:17:54 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

At 06:57:59.00 UT on 28 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200928A (trigger 622969084/ 200928290). This trigger was initially classified as Below Horizon event by the flight software, but is in fact a GRB.

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 58.9, Dec = -14.4(J2000 degrees, equivalent to J2000 3 h 56 m, -14 d 24'), with a statistical uncertainty of 11.7 degrees.

The angle from the Fermi LAT boresight is 68 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200928290/quicklook/glg_skymap_all_bn200928290.png

The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200928290/quicklook/glg_healpix_all_bn200928290.fit

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200928290/quicklook/glg_lc_medres34_bn200928290.gif


GRB_name: GRB200928B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28521
SUBJECT: GRB 200928B: Fermi GBM Final Real-time Localization
DATE:    20/09/28 13:24:54 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 13:14:39 UT on 28 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200928B (trigger 622991684.150156 / 200928552).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 74.5, Dec = -11.6 (J2000 degrees, equivalent to J2000 04h 58m, -11d 35'), with a statistical uncertainty of 2.8 degrees.

The angle from the Fermi LAT boresight is 83.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200928552/quicklook/glg_skymap_all_bn200928552.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200928552/quicklook/glg_healpix_all_bn200928552.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200928552/quicklook/glg_lc_medres34_bn200928552.gif


GRB_name: GRB200928B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28522
SUBJECT: GRB 200928B: BALROG localization (Fermi Trigger 622991684 / GRB 200928552)
DATE:    20/09/28 13:41:28 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
622991684 at 13:14:39 on 28 Sept. 2020 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) = 80.3+/-2.6 deg
Decl.(2000.0) = -10.0+/-3.0 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB200928552/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB200928552/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB200928552/json

                        


GRB_name: GRB200929A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28525
SUBJECT: GRB 200929A: Fermi GBM Final Real-time Localization
DATE:    20/09/29 05:03:31 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 04:53:12 UT on 29 Sep 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200929A (trigger 623047997.2666 / 200929204).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 217.4, Dec = -34.3 (J2000 degrees, equivalent to J2000 14h 29m, -34d 17'), with a statistical uncertainty of 11.5 degrees.

The angle from the Fermi LAT boresight is 47.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200929204/quicklook/glg_skymap_all_bn200929204.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200929204/quicklook/glg_healpix_all_bn200929204.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200929204/quicklook/glg_lc_medres34_bn200929204.gif


GRB_name: GRB200928B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28526
SUBJECT: GRB 200928B: AstroSat CZTI detection
DATE:    20/09/29 08:30:54 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed detection of a long GRB 200928B, which was also detected by Fermi GBM (GCN #28521) and BALROG (Biltzinger B. et al., GCN #28522).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-09-28 13:14:43.203 UT. The measured peak count rate associated with the burst is 221 +/- 22 cts/s above the background in the combined data of four quadrants, with a total of 1755 +/- 19 cts. The local mean background count rate was 448 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 15.20 +/- 0.02 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-09-28 13:14:44.792 UT. The measured peak count rate is 209 +/- 29 cts/s above the background in the combined Veto data of four quadrants, with a total of 1401 +/- 40 cts. The local mean background count rate was 1561 +/- 2  cts/s. We measure a T90 of 15.81 +/- 0.89 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200929A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28527
SUBJECT: Fermi GRB 200929A: Global MASTER-Net observations report 
DATE:    20/09/29 18:00:36 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200929A ( Fermi GBM team, GCN 28525) errorbox  45480 sec after notice time and 45547 sec after trigger time at 2020-09-29 17:32:19 UT, with upper limit up to  18.4 mag. Observations started at twilight.  The observations began at zenith distance = 62 deg. The sun  altitude  is -11.9 deg. 

The galactic latitude b = 24 deg., longitude l = 326 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1450924

We obtain a following upper limits.  

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

   45577 | 2020-09-29 17:32:19 |         MASTER-SAAO | (14h 27m 12.44s , -33d 55m 11.0s) |   C |    60 | 17.9 |        
   45577 | 2020-09-29 17:32:19 |         MASTER-SAAO | (14h 26m 11.75s , -33d 55m 20.0s) |   C |    60 | 17.7 |        
   45657 | 2020-09-29 17:33:39 |         MASTER-SAAO | (14h 28m 59.16s , -35d 56m 07.4s) |   C |    60 | 18.1 |        
   45657 | 2020-09-29 17:33:39 |         MASTER-SAAO | (14h 27m 56.97s , -35d 56m 15.7s) |   C |    60 | 17.9 |        
   45737 | 2020-09-29 17:34:59 |         MASTER-SAAO | (14h 26m 37.00s , -31d 57m 15.2s) |   C |    60 | 17.9 |        
   45737 | 2020-09-29 17:34:59 |         MASTER-SAAO | (14h 25m 37.92s , -31d 57m 22.3s) |   C |    60 | 17.8 |        
   45816 | 2020-09-29 17:36:18 |         MASTER-SAAO | (14h 31m 52.47s , -37d 57m 00.0s) |   C |    60 | 18.2 |        
   45816 | 2020-09-29 17:36:18 |         MASTER-SAAO | (14h 30m 48.73s , -37d 57m 07.2s) |   C |    60 | 18.0 |        
   45896 | 2020-09-29 17:37:38 |         MASTER-SAAO | (14h 27m 14.63s , -33d 55m 18.4s) |   C |    60 | 18.2 |        
   45896 | 2020-09-29 17:37:38 |         MASTER-SAAO | (14h 26m 14.28s , -33d 55m 24.6s) |   C |    60 | 18.0 |        
   45976 | 2020-09-29 17:38:58 |         MASTER-SAAO | (14h 28m 56.76s , -35d 56m 55.7s) |   C |    60 | 18.4 |        
   45976 | 2020-09-29 17:38:58 |         MASTER-SAAO | (14h 27m 54.81s , -35d 57m 01.7s) |   C |    60 | 18.2 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200928B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28533
SUBJECT: GRB 200928B: Insight-HXMT/HE detection
DATE:    20/09/30 01:07:25 GMT
FROM:    Shuo Xiao at IHEP  <xiaoshuo@ihep.ac.cn>

S. Xiao, Y. Q. Zhang, C. Cai, Y. F. Du, Y. G. Zheng, Q. Luo, Q. B. Yi, 
Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, 
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, 
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-09-28T13:14:44.750 (T0), Insight-HXMT/HE detected 
GRB 200928B (trigger ID: HEB200928551) in a routine search of the data, 
which also triggered Fermi-GBM (Fermi GBM team, GCN#28521) and 
AstroSat CZTI (Gupta, GCN#28526).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 14.86 s measured from T0-5.06 s. 
The 1-ms peak rate, measured from T0+1.51 s, is 1437 cnts/sec. 
The total counts from this burst is 9602 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB200928551_lc.jpg 

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 
 
Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB201001A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28538
SUBJECT: GRB 201001A: Fermi GBM Final Real-time Localization
DATE:    20/10/01 10:09:20 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 09:59:00 UT on 1 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201001A (trigger 623239145.485614 / 201001416).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 111.3, Dec = 6.5 (J2000 degrees, equivalent to J2000 07h 25m, 6d 30'), with a statistical uncertainty of 3.9 degrees.

The angle from the Fermi LAT boresight is 18.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201001416/quicklook/glg_skymap_all_bn201001416.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201001416/quicklook/glg_healpix_all_bn201001416.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201001416/quicklook/glg_lc_medres34_bn201001416.gif


GRB_name: GRB201001A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28539
SUBJECT: GRB 201001A: Swift detection of a burst
DATE:    20/10/01 10:19:55 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. K. Simpson (PSU), J.D. Gropp (PSU), H. A. Krimm (NSF),
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 09:58:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201001A (trigger=998344).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 110.070, -2.210 which is 
   RA(J2000) = 07h 20m 17s
   Dec(J2000) = -02d 12' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 30 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 10:00:47.5 UT, 116.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 110.0806, -2.2103 which
is equivalent to:
   RA(J2000)  = 07h 20m 19.33s
   Dec(J2000) = -02d 12' 37.2"
with an uncertainty of 4.4 arcseconds (radius, 90% containment). This
location is 38 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. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 119 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
0.12. 

Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 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: GRB201001A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28540
SUBJECT: GRB 201001A: Enhanced Swift-XRT position
DATE:    20/10/01 13:49:40 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 1430 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 201001A, 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 = 110.08086, -2.21102 which is equivalent
to:

RA (J2000): 07h 20m 19.41s
Dec (J2000): -02d 12' 39.7"

with an uncertainty of 3.1 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: GRB201001A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28542
SUBJECT: GRB 201001A: Fermi GBM observation
DATE:    20/10/01 17:53:44 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH), A. von Kienlin (MPE) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 09:59:00.49 UT on 1 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201001A (trigger 623239145 / 201001416)
which was also detected by the Swift/BAT (Simpson et al., GCN 28539).
The Fermi GBM Final Real-time Localization (GCN 28538) is consistent
with the Swift position.


The angle from the Fermi LAT boresight at the GBM trigger time is 18 degrees.


The GBM light curve shows a  single pulse
with a duration (T90) of about 15.6 s (50-300 keV).
The time-averaged spectrum from T0-10.2 s to T0+12.3 s is
best fit by a Band function with Epeak = 71 +/- 21 keV,
alpha = 0.81 +/- 1.11, and beta = -1.91 +/- 0.15.

The event fluence (10-1000 keV) in this time interval is
(9.6 +/- 5.6)E-7 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-2.3 s in the 10-1000 keV band
is 1.7 +/- 0.2 ph/s/cm^2.


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

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


GRB_name: GRB201001A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28544
SUBJECT: GRB 201001A: Swift-XRT refined Analysis
DATE:    20/10/01 18:51:48 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 6.2 ks of XRT data for GRB 201001A (Simpson et al. GCN
Circ. 28539), from 129 s to 24.5 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN Circ. 28540). The source
is fading with alpha >0.5.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00998344.

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


GRB_name: GRB201001A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28545
SUBJECT: GRB 201001A: Swift-BAT refined analysis
DATE:    20/10/01 20:46:52 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),  H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), K. K. Simpson (PSU),
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 201001A (trigger #998344)
(Simpson, et al., GCN Circ. 28539).  The BAT ground-calculated position is
RA, Dec = 110.050, -2.213 deg which is 
  RA(J2000)  =  07h 20m 12.0s 
  Dec(J2000) = -02d 12' 48.3" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 38%.

The mask-weighted light curve shows a broad single peak of duration roughly 
20 seconds, from ~T-5 to ~T+15 sec.  T90 (15-350 keV) is 15.2 +- 2.7 sec (estimated 
error including systematics).

The time-averaged spectrum from T-4.02 to T+12.98 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.96 +- 0.23.  The fluence in the 15-150 keV band is 7.6 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+10.79 sec in the 15-150 keV band
is 1.0 +- 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/998344/BA/


GRB_name: GRB201001A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28548
SUBJECT: GRB 201001A: MITSuME Akeno optical upper limits
DATE:    20/10/02 09:42:14 GMT
FROM:    Ryohei Hosokawa at Tokyo Institute of Technology  <hosokawa@hp.phys.titech.ac.jp>

R. Hosokawa, S. Ogata, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa,
N. Nakamura, N. Ito, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai
(TokyoTech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 201001A(Fermi GBM Team, GCN 28538; David
et al., GCN 28539) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.

The observation with a series of 60 sec exposures started at
2020-10-01 16:44:38UT. Since some images were heavily affected by the
moon, we stacked the images with good conditions. We did not find any
new point sources within the enhanced Swift/XRT error circle (Evans et
al., GCN 28540) in the 60 sec exposure images and the stacked images.
We obtained the 5-sigma limits of the stacked images as follows.

T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
6.8 2020-10-01T19:06:10.46 4020 g'>19.0, Rc>19.3, Ic>18.9
------------------------------------------------------------------------------------------------
T0+: Elapsed time after the burst
T-EXP: Total Exposure time

We used the 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., accepted
for publication in PASJ, https://arxiv.org/abs/2008.11486;
https://github.com/MNiwano/Eclaire).

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GRB_name: GRB201001A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28549
SUBJECT: GRB 201001A: Xinglong-2.16m optical upper limit
DATE:    20/10/02 13:15:29 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

S.Y. Fu, Z.P. Zhu, X. Liu, D. Xu (NAOC) report:

We observed the field of GRB 201001A (Simpson et al., GCN 28539) using 
the Xinglong-2.16m telescope equipped with the BFOSC camera. 
Observations were carried out starting at 19:29:17 UT on 2020-10-01 
(i.e., about 9.5 hr after the BAT trigger), and 10x180s, 9x360s R-band 
frames were obtained.

No optical source is detected in our stacked image at the enhanced XRT 
position (Evans et al., GCN 28540), down to a upper limit of R~21.0, 
calibrated with the nearby PanSTARRS field.

We acknowledge great support from the Xinglong-2.16m observing staff, in 
particular J. Zheng and A.Y. Zhou.


GRB_name: GRB201001A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28550
SUBJECT: GRB 201001A: TSHAO optical upper limit
DATE:    20/10/02 14:39:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), I. Reva (FAPHI), A. Pozanenko (IKI)  report on behalf 
of GRB-IKI-FuN:

We observed the field of GRB 201001A (Simpson et al., GCN 28539) with 
Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting 
on Oct. 01 (UT) 22:56:08.

No optical source is detected within enhanced Swift-XRT position (Evans 
et al., GCN 28540). This corresponds to the absence of the source in 
earlier optical observations (Simpson et al., GCN 28539;  Hosokawa et 
al., GCN 28548; Fu et al., GCN 28549).  Preliminary photometry of the 
field is following.

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

2020-10-01 22:56:08 0.54732  R      22*50 n/d   n/d  20.3

The photometry is based on nearby USNO-B1.0 star.

USNO-B1.0_id R2
0877-0204059 15.98


GRB_name: GRB201001A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28555
SUBJECT: GRB 201001A: Swift/UVOT Upper Limits
DATE:    20/10/03 19:24:16 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>

A. Belles (PSU) and K. K. Simpson (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201001A
120 s after the BAT trigger (Simpson et al., GCN Circ. 28539).
No optical afterglow consistent with the XRT position
(Simpson et al. GCN Circ. 28539)
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           120          270          147         >21.1
u_FC               279          529          246         >19.8
white              120         1525          392         >21.1
v                  611         1575          117         >18.8
b                  535         1501           97         >18.9
u                  279         1476          324         >19.8
w1                 660         1452           97         >19.1
m2                 635         1427           97         >19.7
w2                 586         1550          117         >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.12 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB201004A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28557
SUBJECT: GRB 201004A: Fermi GBM Final Localization
DATE:    20/10/04 13:23:10 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

At 08:45:57.61 UT on 4 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 201004A (trigger 623493962/ 201004365). This
trigger was initially classified as Distant Particles event by the flight
software, but is in fact a GRB.

The on-ground calculated location, using the Fermi GBM trigger data, is RA =
30.1, Dec = 61.2(J2000 degrees, equivalent to J2000 2 h 00 m, 61 d 12'),
with a statistical uncertainty of 4.3 degrees.

The angle from the Fermi LAT boresight is 142 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201004365/q
uicklook/glg_skymap_all_bn201004365.png

The HEALPix FITS file, including the estimated localization systematic, can
be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201004365/q
uicklook/glg_healpix_all_bn201004365.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201004365/q
uicklook/glg_lc_medres34_bn201004365.gif


GRB_name: GRB141121A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  17108
SUBJECT: Konus-Wind observation of GRB 141121A
DATE:    14/11/28 14:34:54 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 141121A (Swift-BAT trigger #619182: Lien et al., GCN 17075;
Krimm et al., GCN 17083; MAXI/GSC detection: Honda et al., GCN 17077)
was detected by Konus-Wind in the waiting mode.

The burst light curve shows two emission episodes. The first started at 
~T0(BAT)-870 s with a duration of about 190 s and the second weaker 
episode, which corresponds to the first BAT episode reported in GCN 
17075, started at ~T0(BAT)+50 s with a duration of about 270 s. The 
second BAT episode (from T0(BAT)+550 to T0(BAT)+675 s) is not seen in KW 
data.

The first KW episode is likely related to GRB 141121A, since the KW 
ecliptic latitude response and IPN localization of the episode are 
consistent with the position of GRB 141121A. The details of the IPN 
localization will be given in a forthcoming GCN circular. During the 
first episode the burst source was outside the BAT FoV (private 
communication with the BAT team).

The total burst duration is about 1200 s. Such a long duration and long 
periods of low-level emission or quiescence is common for ultra-long GRB.

The KW light curve contains several data gaps. One of them (from 
~T0(BAT)-670 s to ~T0(BAT)-270 s) may bias the estimated duration of the 
first episode. The MAXI/GSC detection at ~T0(BAT)-356 s falls into this gap.

As observed by Konus-Wind, the first episode had a fluence of ~8x10^-6 
erg/cm2 and a 2.944 s peak flux, measured from ~T0(BAT)-752 s, of 
~2x10^-7 erg/cm2/s (both estimated in the 20 keV - 10  MeV energy 
range). The second episode had a fluence of ~6x10^-6 erg/cm2 estimated 
in the same energy range.

Assuming the redshift z=1.47 (Perley et al., GCN 17081)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~8x10^52 erg,
the peak luminosity L_iso is ~10^51 erg/s.

The K-W light curve of this burst is available at
http://www.ioffe.ru/LEA/GRBs/GRB141121A/


GRB_name: GRB201006A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28560
SUBJECT: GRB 201006A: Swift detection of a burst
DATE:    20/10/06 01:31:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

J.D. Gropp (PSU), S. D. Barthelmy (GSFC), S. Laha (GSFC/UMBC/CRESST),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), B. Sbarufatti (PSU),
M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 01:17:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201006A (trigger=998907).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 61.880, +65.150 which is 
   RA(J2000)  =  04h 07m 31s
   Dec(J2000) = +65d 08' 59"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
structure with a duration of about 5 sec.  The peak count rate
was ~2500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 01:19:15.9 UT, 83.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 61.8932, 65.1650 which
is equivalent to:
   RA(J2000)  = 04h 07m 34.36s
   Dec(J2000) = +65d 09' 54.0"
with an uncertainty of 2.6 arcseconds (radius, 90% containment). This
location is 57 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 4.50
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 87 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
1.27. 

Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB201006A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28561
SUBJECT: INTEGRAL sub-threshold detection of GRB 201006A
DATE:    20/10/06 07:51:46 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 201006A detected by Swift (Gropp et al., GCN 28560) has been also
revealed as a sub-threshold GRB by IBAS  in the  IBIS/ISGRI data. The
corresponding WEAK type Alert Packet with the burst position was
distributed in real time  (Alert n. 8745).

The burst coordinates (J2000) obtained with the offline analysis of the
IBIS/ISGRI data are:

R.A.= 61.9045 deg
DEC.= +65.1478  deg

with an uncertainty of 3 arcmin (90% c.l.).


GRB_name: GRB201006A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28562
SUBJECT: GRB 201006A: Enhanced Swift-XRT position
DATE:    20/10/06 09:19:20 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 1436 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 201006A, 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 = 61.89270, +65.16462 which is equivalent
to:

RA (J2000): 04h 07m 34.25s
Dec (J2000): +65d 09' 52.6"

with an uncertainty of 2.1 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: GRB201006A
Detection_method: IBAS
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28563
SUBJECT: GRB 201006A is likely a short burst
DATE:    20/10/06 17:04:58 GMT
FROM:    Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>

GRB 201006A, detected by Swift/BAT (Gropp et al. GCN 28560),
INTEGRAL/IBAS (Mereghetti et al. GCN 28561) and Fermi/GBM (trig num
623639877), appears likely to be a short burst, despite the real-time
duration estimate (~5s) reported in GCN 28560.
The T90 estimate from downlinked Swift/BAT event data is less than 0.5 seconds.
Follow-up is encouraged.


GRB_name: GRB201006A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28564
SUBJECT: GRB 201006A: Fermi GBM detection
DATE:    20/10/06 17:14:45 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

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

"At 01:17:52.27 UT on 06 October 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 201006A (trigger 623639877 / 201006054),
which was also detected by the Swift/BAT and the Swift/XRT
(Gropp et al. 2020, GCN 28560). The GBM on-ground location is
consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 42
degrees.

The GBM light curve consists of one main spike
with a duration (T90) of about 1.7 s (50-300 keV).
The time-averaged spectrum from T0-0.19 s to T0+0.83 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.97 +/- 0.19 and
the cutoff energy, parameterized as Epeak, is 130 +/- 26 keV.

The event fluence (10-1000 keV) in this time interval is
(3.33 +/- 0.38)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band
is 6.86 +/- 0.97 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: GRB201006A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28565
SUBJECT: GRB 201006A: Swift/UVOT Upper Limits
DATE:    20/10/06 21:07:13 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and J. D. Gropp (PSU)

report on behalf of the Swift/UVOT team:



The Swift/UVOT began settled observations of the field of GRB 201006A

88 s after the BAT trigger (Gropp et al., GCN Circ. 28560).

No optical afterglow consistent with the XRT position

(Goad et al. GCN Circ. 28562)

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            88          238          147         >21.1

u_FC               300          549          246         >20.2

white               88         1539          385         >21.0

v                  629         1423           97         >18.9

b                  555         1521           97         >19.8

u                  300          722          265         >20.3

w1                 678         1472           97         >18.7

w2                1205         1225           19         >17.3



The magnitudes in the table are not corrected for the Galactic extinction

due to the reddening of E(B-V) = 1.27 in the direction of the burst

(Schlegel et al. 1998).


GRB_name: GRB201006A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28567
SUBJECT: GRB 201006A: Swift-BAT refined analysis
DATE:    20/10/06 23:22:00 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
J. D. Gropp (PSU), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 201006A (trigger #998907)
(Group et al., GCN Circ. 28560).  The BAT ground-calculated position is
RA, Dec = 61.917, 65.148 deg which is
   RA(J2000)  =  04h 07m 40.1s
   Dec(J2000) = +65d 08' 53.3"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 33%.

The mask-weighted light curve shows a pulse that starts and peaks at ~T0,
and ends at ~T+0.5 s. T90 (15-350 keV) is 0.49 +- 0.09 sec (estimated error
including systematics).

The time-averaged spectrum from T-0.01 to T+0.54 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.42 +- 0.24.  The fluence in the 15-150 keV band is
1.3 +- 0.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T-0.23 sec in the 15-150 keV band is 2.2 +- 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/998907/BA/


GRB_name: GRB201006A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28568
SUBJECT: GRB 201006A: Swift-XRT refined Analysis
DATE:    20/10/07 01:31:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J. D. Gropp (PSU), 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) , J.A. Kennea (PSU),
A. Tohuvavohu (U. Toronto) and J.D. Gropp report on behalf of the
Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 201006A (Gropp et al. GCN
Circ. 28560), from 91 s to 70.3 ks after the  BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Goad et al. (GCN Circ. 28562).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.99 (+0.14, -0.13).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.1 (+/-0.6). The
best-fitting absorption column is  1.3 (+0.7, -0.5) x 10^22 cm^-2, in
excess of the Galactic value of 4.5 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 4.9 x 10^-11 (1.1 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.3 (+0.7, -0.5) x 10^22 cm^-2
Galactic foreground: 4.5 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index:      2.1 (+/-0.6)

If the light curve continues to decay with a power-law decay index of
0.99, the count rate at T+24 hours will be 4.0 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x
10^-14 (4.3 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00998907.

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


GRB_name: GRB201007A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28569
SUBJECT: GRB 201007A: Fermi GBM Final Real-time Localization
DATE:    20/10/07 03:06:55 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 02:56:38 UT on 7 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201007A (trigger 623732203.167578 / 201007123).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 297.0, Dec = 2.6 (J2000 degrees, equivalent to J2000 19h 48m, 2d 36'), with a statistical uncertainty of 3.4 degrees.

The angle from the Fermi LAT boresight is 51.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201007123/quicklook/glg_skymap_all_bn201007123.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201007123/quicklook/glg_healpix_all_bn201007123.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201007123/quicklook/glg_lc_medres34_bn201007123.gif


GRB_name: GRB201007A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28570
SUBJECT: Fermi GRB 201007A: Global MASTER-Net observations report 
DATE:    20/10/07 03:45:11 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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) started inspect of the Fermi GRB 201007A ( Fermi GBM team, GCN 28569) errorbox  22 sec after notice time and 92 sec after trigger time at 2020-10-07 02:58:10 UT, with upper limit up to  18.2 mag. The observations began at zenith distance = 63 deg. The sun  altitude  is -48.3 deg. 

The galactic latitude b = -12 deg., longitude l = 42 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1457091

We obtain a following upper limits.  

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

     102 | 2020-10-07 02:58:10 |         MASTER-OAFA | (19h 41m 51.88s , +02d 16m 42.9s) |   C |    20 | 17.0 |        
     127 | 2020-10-07 02:58:10 |         MASTER-OAFA | (19h 41m 51.88s , +02d 16m 42.9s) |   C |    70 | 17.6 |  Coadd 
     141 | 2020-10-07 02:58:49 |         MASTER-OAFA | (19h 41m 51.38s , +02d 17m 43.0s) |   C |    20 | 17.1 |        
     186 | 2020-10-07 02:59:29 |         MASTER-OAFA | (19h 41m 57.45s , +02d 16m 44.4s) |   C |    30 | 17.2 |        
     241 | 2020-10-07 03:00:19 |         MASTER-OAFA | (19h 41m 52.34s , +02d 15m 45.3s) |   C |    40 | 17.4 |        
     301 | 2020-10-07 03:00:19 |         MASTER-OAFA | (19h 41m 52.34s , +02d 15m 45.4s) |   C |   160 | 17.9 |  Coadd 
     306 | 2020-10-07 03:01:18 |         MASTER-OAFA | (19h 41m 58.36s , +02d 16m 14.1s) |   C |    50 | 17.5 |        
     385 | 2020-10-07 03:02:28 |         MASTER-OAFA | (19h 41m 55.03s , +02d 17m 35.1s) |   C |    70 | 17.5 |        
     472 | 2020-10-07 03:04:00 |         MASTER-OAFA | (19h 39m 25.87s , +01d 16m 37.7s) |   C |    60 | 17.4 |        
     551 | 2020-10-07 03:05:19 |         MASTER-OAFA | (19h 41m 30.80s , +03d 16m 34.9s) |   C |    60 | 17.3 |        
     661 | 2020-10-07 03:06:39 |         MASTER-OAFA | (19h 46m 32.52s , +01d 49m 05.4s) |   C |   120 | 17.7 |        
     826 | 2020-10-07 03:06:39 |         MASTER-OAFA | (19h 46m 32.52s , +01d 49m 05.5s) |   C |   450 | 18.2 |  Coadd 
     815 | 2020-10-07 03:08:58 |         MASTER-OAFA | (19h 46m 25.19s , +01d 48m 05.3s) |   C |   150 | 17.8 |        
    1000 | 2020-10-07 03:11:48 |         MASTER-OAFA | (19h 46m 31.54s , +01d 48m 27.0s) |   C |   180 | 17.8 |        
    1199 | 2020-10-07 03:15:07 |         MASTER-OAFA | (19h 46m 28.53s , +01d 49m 41.8s) |   C |   180 | 17.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201006A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28571
SUBJECT: GRB 201006A: MITSuME Akeno optical upper limits
DATE:    20/10/07 10:07:26 GMT
FROM:    Naohiro Ito at Tokyo Tech  <n.ito@hp.phys.titech.ac.jp>

N. Ito, R. Hosokawa, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa, N.
Nakamura, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai
(TokyoTech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 201006A (J.D. Gropp et al.,GCN #28560,
S.Mereghetti et al., GCN #28561, R. Hamburg et al., GCN # 28564) with
the optical three color (g', Rc, and Ic) CCD cameras attached to the
MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started at 13:31:53 UT. Since some images were heavily
affected by bad weather and the moon, we stacked the images with good
conditions. We did not find any new point sources within the enhanced
Swift/XRT circle (M.R. Goad et al., GCN #28562) in all three bands.
We obtained the 5-sigma limits as follows.
T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
12.2 16:27:01 4020.0 g'>19.5,Rc>19.4,Ic>18.9
------------------------------------------------------------------------------------------------
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., accepted for publication in PASJ;
arXiv2008.11486
https://github.com/MNiwano/Eclaire)


GRB_name: GRB201006A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28572
SUBJECT: GRB 201006A: Lowell Discovery Telescope upper limits
DATE:    20/10/07 14:35:50 GMT
FROM:    Simone Dichiara at UMCP/NASA/GSFC  <dichiara@umd.edu>

S.Dichiara (UMD, NASA-GSFC), S.B. Cenko (NASA-GSFC), E. Troja (UMD,
NASA-GSFC), P. Gatkine (UMD), J.M. Durbak (UMD), A. Kutyrev (UMD,
NASA-GSFC), S. Veilleux (UMD), report on behalf of a larger
collaboration:

We observed the field of the short GRB 201006A (Gropp et al., GCN Circ.
28560) using the Large Monolithic Imager (LMI) on the 4.3m Lowell
Discovery Telescope (LDT) at Happy Jack, AZ. Observations started on
October 7, 11:50:54 UT (1.44 days after the Swift trigger) taking 3
exposures of 150 s each with SDSS i filter. Observations were taken at
an airmass of about 1.19 and seeing of about 0.5".
We do not find any source inside the enhanced XRT position  (Goad et
al., GCN Circ. 28562) down to a 3-sigma limiting magnitude of i>23.8
AB mag.
Magnitudes are calibrated against the PanSTARRS catalog and not corrected
for Galactic extinction.

We thank the staff of the Lowell Discovery Telescope for assistance with
these observations.


GRB_name: GRB201006A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28573
SUBJECT: GRB 201006A: GROWTH-India Telescope optical upper limit
DATE:    20/10/07 18:48:47 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), J. Stanzin (IAO), V. Bhalerao(IITB), G. C. Anupama(IIA),
S. Barway(IIA), report on behalf of the GROWTH-India collaboration:

We observed GRB 201006A reported by Swift-BAT (J.D. Gropp et al., GCN
28560; also see: S.Mereghetti et al., GCN 28561; M.R. Goad et al., GCN
28562; Aaron Tohuvavohu GCN 28563; R. Hamburg and C. Meegan, GCN 28564; F.
E. Marshall and J. D. Gropp GCN 28565; S. D. Barthelmy et al., GCN 28567;
J. D. Gropp et al., GCN 28568; N. Ito et al., 28571, S.Dichiara et al., GCN
28572) with 0.7m GROWTH-India Telescope (GIT). The field was observed in
the SDSS râ€™ filter starting at 2020-10-06T18:32:40.4 UT i.e. ~17.25 hrs
after the event detection by Swift-BAT. We obtained 20 exposures of 300 sec
each. The field was close to the moon (~43 deg) during observations. We did
not find any source in the stacked image within the uncertainty region of
2.1 arcsec around the Swift-XRT position of RA(J2000): 04h 07m 34.25s,
Dec(J2000): +65d 09' 52.6" (GCN  28562). We obtained an upper limit of r >
20.09 mag, calibrated against PanSTARRs PS1 data release (Flewelling et
al., 2018).

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 and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB201008A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28577
SUBJECT: GRB 201008A: BALROG localization (Fermi Trigger 623846261 / GRB 201008443)
DATE:    20/10/08 11:04:12 GMT
FROM:    Jochen Greiner at MPE,Garching  <jcg@mpe.mpg.de>

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

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
623846261 at 10:37:36 on 08 Oct. 2020 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) = 167.1+/-4.3 deg
Decl.(2000.0) = 42.1+/-3.9 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB201008443/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB201008443/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB201008443/json

                        


GRB_name: GRB201008A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28583
SUBJECT: GRB 201008A: Swift/BAT-GUANO detection and possible arcminute localization
DATE:    20/10/08 22:41:45 GMT
FROM:    James DeLaunay at PSU  <jjd330@psu.edu>

James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Jamie Kennea (PSU),
Peter Veres (UAH) report:

Swift/BAT did not trigger on GRB 201008A (T0: 2020-10-08 10:37:36 UTC,
Fermi/GBM Team TRIGGER 623846261).

The Fermi/GBM 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 burst is detected in BAT with a T90 duration of ~2.5 seconds.

With a maximum likelihood analysis (DeLaunay et al. 2020, in prep.) on

the event-mode data we detect a location for the burst with a square

root of the test statistic, sqrt(TS), of 13.22. The sqrt(TS) behaves

similarly to SNR.

Using the normal BAT imaging technique, we find the location of the GRB
with an SNR of 4.2.

Since this is a low significance detection near the edge of the coded field
of view there is a chance that this localization may be incorrect.

The BAT ground-calculated position is

RA, Dec = 161.744, 46.101 deg which is

   RA(J2000)  = 10h 46m 58.56s

   Dec(J2000) =  46d 06â€™ 03.6â€

with an uncertainty of 5 arcmin, (radius, sys+stat, 90% containment).

The partial coding was 3.5%.

This position is consistent with the Fermi GBM localization (
https://gcn.gsfc.nasa.gov/other/623846261.fermi) and BALROG localization
(GCN 28577).

XRT and UVOT follow-up has been triggered. 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: GRB201008A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28585
SUBJECT: GRB 201008A: Swift ToO observations
DATE:    20/10/08 23:40:25 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 201008A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021034

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: GRB201008A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28587
SUBJECT: GRB 201008A: Swift-XRT observations
DATE:    20/10/09 08:43:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M.G.
Bernardini (INAF-OAB), E. Ambrosi  (INAF-IASFPA) , M. Capalbi
(INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B.
Sbarufatti (PSU) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the Fermi/GBM and
Swift/BAT-GUANO detected burst GRB 201008A (DeLaunay et al. GCN Circ.
28583), collecting 4.5 ks of Photon Counting (PC) mode data between
T0+46.9 ks and T0+60.1 ks. 

Two uncatalogued X-ray sources have been detected consistent with being
within 296 arcsec of the BAT/GUANO 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):  161.7543  =  10:47:1.02
  Dec (J2000): +46.1475  =  +46:08:51.1
  Error: 5.1 arcsec (radius, 90% conf.)
  Count-rate: (1.79 [+1.09, -0.80])e-3 ct s^-1  
  Distance: 169 arcsec from BAT position.
  NB, this position is consistent with SDSS J104701.20+460848.8,
  a likely quasar in the SDSS Quasar Catalogue. If this association
  and ID is accurate, this source is unlikely to be related to the GRB.


Source 4:
  RA (J2000):  161.8588  =  10:47:26.10
  Dec (J2000): +46.1019  =  +46:06:06.9
  Error: 4.8 arcsec (radius, 90% conf.)
  Count-rate: (4.1 [+1.3, -1.1])e-3 ct s^-1   
  Distance: 286 arcsec from BAT position.
  Flux: (1.68 [+0.52, -0.44])e-10 erg cm^-2 s^-1 (observed, 0.3-10 keV)


Two 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/00021034.

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


GRB_name: GRB201009A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28588
SUBJECT: GRB 201009A: AGILE detection of a burst
DATE:    20/10/09 10:19:29 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

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

A few seconds after emerging from the SAA, the AGILE satellite detected a
burst, with a MCAL trigger at T0 = 2020-10-09 03:08:26 (UT). The event is
visible in the scientific ratemeters of the SuperAGILE (SA; 18-60 keV),
MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV)
detectors. The event lasted about ~6 s and released 1045 counts in the SA
detector (above a background rate of 74 Hz), 24910 counts in the MCAL
detector (above a background rate of 1176 Hz), and 43490 counts in the AC
detector (above a background rate of 3523 Hz). The AGILE RM light curves
can be found at:
http://www.agilescienceapp.it/notices/GRB201009A_AGILE_RMs.png . The event
could have possibly started earlier, as shown in the SuperAGILE light curve.

The event also triggered a partial high time resolution MCAL data
acquisition.

Additional analysis of AGILE data is in progress.


GRB_name: GRB201009A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28589
SUBJECT: GRB 201009A: AstroSat CZTI detection
DATE:    20/10/09 10:48:43 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed detection of a bright long GRB 201009A, which is also detected by AGILE (Ursi A. et al., GCN #28588).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-09 03:08:21.500 UT. The measured peak count rate associated with the burst is 4215 +/- 69 cts/s above the background in the combined data of four quadrants, with a total of 45310 +/- 77 cts. The local mean background count rate was 516 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 40.20 +/- 0.13 s.  In a preliminary analysis, we find that 3509 Compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-09 03:08:21.000 UT. The measured peak count rate is 12953 +/- 121 cts/s above the background in the combined Veto data of four quadrants, with a total of 71480 +/- 124 cts. The local mean background count rate was 1534 +/- 2  cts/s. We measure a T90 of 26.64 +/- 0.12 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB201008B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28591
SUBJECT: GRB 201008B: Fermi GBM Final Localization
DATE:    20/10/09 15:06:19 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 18:06:00.94 UT on 8 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201008B (trigger 623873165 / 201008754).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 90.8, Dec = 39.3 (J2000 degrees, equivalent to J2000 6h 3m, +39d 18'), with a statistical uncertainty of 4.0 degrees.

The angle from the Fermi LAT boresight is 62.1 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201008754/quicklook/glg_skymap_all_bn201008754.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201008754/quicklook/glg_healpix_all_bn201008754.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201008754/quicklook/glg_lc_medres34_bn201008754.gif


GRB_name: GRB201010A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28594
SUBJECT: Swift detection of a new SGR 1830-0645 or a short GRB 201010A
DATE:    20/10/10 15:16:16 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

K. L. Page (U Leicester), S. D. Barthelmy (GSFC),
N. J. Klingler (PSU), N. P. M. Kuin (UCL-MSSL) and
A. Y. Lien (GSFC/UMBC) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 14:49:24 UT, the Swift Burst Alert Telescope (BAT) triggered and
located SGR 1830-0645 or GRB 201010A (trigger=999571).  
Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 277.675, -6.758, which is 
   RA(J2000)  =  18h 30m 42s
   Dec(J2000) = -06d 45' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
structure with a duration of no more than 0.128 sec.  The peak count rate
was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 14:50:30.9 UT, 67.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 277.6702, -6.7550 which
is equivalent to:
   RA(J2000)  = 18h 30m 40.85s
   Dec(J2000) = -06d 45' 18.0"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 20 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 consistent with the Galactic value of 1.11
x 10^22 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 71 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. Because of the density of catalogued stars, further
analysis is required to report an upper limit for any afterglow in the
sub-image. The 8'x8' region for the list of sources generated on-board covers
100% of the XRT error circle. Because of the density of catalogued stars,
further analysis is required to report an upper limit for any afterglow in the
region. No correction has been made for the large, but uncertain, extinction
expected. 

Due to its short duration (BAT trigger duration of 8 ms, although 
the immediately available lightcurve is only available at 128 ms 
resolution), the soft spectrum (not visible above 50 keV) and its
location in the Galactic bulge near the plane (lon,lat) = (24.5, 1.5)
we suspect that this event may be a new Soft Gamma Repeater, which
we would name SGR 1830-0645. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 
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: GRB201010A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28596
SUBJECT: GRB 201010A: Enhanced Swift-XRT position
DATE:    20/10/10 20:59:12 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 2915 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 201010A, 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 = 277.67385, -6.75455 which is equivalent
to:

RA (J2000): 18h 30m 41.72s
Dec (J2000): -06d 45' 16.4"

with an uncertainty of 1.4 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: GRB201010A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28597
SUBJECT: SGR 1830-0645 / GRB 201010A: Kitab optical non-detection
DATE:    20/10/11 12:42:25 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI), A. Zhornichenko (KIAM), N. Pankov 
(HSE), A. Novichonok (Petrozavodsk State University, KIAM),   Sh. 
Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN:

We observed the field of new SGR 1830-0645 (Page et al., GCN 28594; 
Gogus et al., ATEL 14085) originally detected by Swift (trigger=999571) 
and also named as GRB 201010A with Kitab-ISON RC-36  telescope in 
R-filter. Observation started on Oct. 10 (UT) 15:21:08, i.e. 31.7 
minutes after trigger.

The field is extremely crowded. Within  enhanced XRT position (Osborne 
et al., GCN 28596) we found  a source which is also presented in the 
DSS2 (R) image but not listed in USNO-B1.0. In our images we cannot 
discriminate the sources. We performed aperture photometry which include 
this source and nearby Northern source listed in USNO-B1.0 0832-0432584 
(R2=13.54) in two stacked images. The image A is at midpoint 0.02343 
days and the image (B) is at midpoint 0.03835 days after trigger. By 
comparison of the two photometric results (A) R=14.16 +/- 0.06 and (B) 
R=14.20 +/- 0.07 we do not observe any variability and hence we do not 
detect optical activity of SGR 1830-0645.

Formal photometry of the field in both epochs (A,B) is following

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

(A)2020-10-10  15:21:08 0.02343   240    R       n/d    n/d   17.0
(B)2020-10-10  15:21:08 0.03835  2480    R       n/d    n/d   18.0

The photometry is based on nearby USNO-B1.0 star, R2 magnitude

USNO_B10_id  R2
0832-0432530 15.34
0832-0433055 13.04


GRB_name: GRB201006A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28598
SUBJECT: GRB 201006A: Chandra upper limit on the X-ray afterglow
DATE:    20/10/11 17:30:25 GMT
FROM:    Alicia Rouco Escorial at CIERA  <alicia.rouco.escorial@northwestern.edu>

A. Rouco Escorial, W. Fong, G. Schroeder, K. Paterson, C. D. Kilpatrick, A. Nugent, J. Rastinejad, R. Margutti, K. D. Alexander (Northwestern), T. Laskar (Bath), and E. Berger (Harvard) report:

We initiated observations with the Chandra X-ray Observatory of the short-duration GRB 201006A (Barthelmy et al., GCN 28560; Tohuvavohu, GCN 28563; Hamburg et al., GCN 28564; Lien et al., GCN 28567) starting on 2020 October 09 20:57:42 UT, with a median observation time of 3.98 days post-trigger. We obtained one ACIS-S observation under the Proposal 21400447 (ObsID 22401; PI: Fong), with an effective exposure time of 24.7 ks.

We do not detect an X-ray source within the enhanced Swift-XRT position (90% confidence; Evans et al., GCN 28562). Centered on the XRT position, we obtain a 3-sigma limit of <3.6e-4 cts/s in the 0.5-8 keV energy range (following Gehrels 1986). Applying the best-fit PC-mode XRT spectral parameters (Gamma=2.1, total NH=1.3e22 cm^-2; Evans et al., GCN 28568), we calculate a 3-sigma unabsorbed flux limit of FX<1.15e-14 erg/s/cm^2 in the 0.3-10 keV energy range.

The XRT afterglow, starting at ~153.3 s post-burst, can be modeled with a power law decline (where FX~t^alpha) with a decay index of alpha=-0.99(+0.14,-0.13) consistent with the results of Evans et al. (GCN 28568). Our Chandra upper limit is marginally consistent with the expected flux at dt~3.98 days drawn by this model.

We thank the Chandra Director, Patrick Slane, and staff for the rapid planning and scheduling of these observations.


GRB_name: GRB201010A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28601
SUBJECT: SGR 1830-0645 / GRB 201010A: 1.5m OSN optical upper limit
DATE:    20/10/11 19:35:27 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

Y.-D. Hu, A. Sota, A. J. Castro-Tirado, E. Fernandez-Garcia (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga) on behalf of a larger collaboration, report:

Following the detection of SGR 1830-0645/GRB201010A by Swift (Page et al. GCNC 28594), optical images in the I-band were obtained at the 1.5m OSN telescope in Granada (Spain) starting at 20:35 (Oct 10), i.e. ~5.8 h postburst. No optical afterglow is detected in the image within the enhanced Swift/XRT error box (Osborne et al. GCNC 28596) down to I=20.1, which is in agreement with the non-detections reported by Lipunov et al. (GCNC 28595) and Belkin et al. (GCNC 28597).

We thank the staff at OSN for their excellent support.


GRB_name: GRB201012A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28604
SUBJECT: GRB 201012A: Fermi GBM Final Real-time Localization
DATE:    20/10/12 05:46:04 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 05:35:38 UT on 12 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201012A (trigger 624173743.502338 / 201012233).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 303.7, Dec = -33.5 (J2000 degrees, equivalent to J2000 20h 14m, -33d 30'), with a statistical uncertainty of 3.4 degrees.

The angle from the Fermi LAT boresight is 57.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201012233/quicklook/glg_skymap_all_bn201012233.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201012233/quicklook/glg_healpix_all_bn201012233.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201012233/quicklook/glg_lc_medres34_bn201012233.gif


GRB_name: GRB201011A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28606
SUBJECT: GRB 201011A: Fermi GBM detection of a likely Long GRB in the direction of SGR 1830-0645
DATE:    20/10/12 21:10:54 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>

O.J. Roberts (USRA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 15:06:24.66 UT on 11 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201011A (trigger 624121589 / 201011629),
which was also detected by the AGILE (Ursi et al. 2020, GCN 28605).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 281.1, Dec = -5.7 (J2000 degrees, equivalent to
J2000 18h 44m , -05d 43'), with a statistical uncertainty of 2.4 degrees.

The angle from the Fermi LAT boresight at the GBM trigger time is 35 degrees.

The GBM light curve consists of multiple pulses
with a duration (T90) of about 126.2 s (50-300 keV).
The time-averaged spectrum from T0-1.8 s to T0+124.2 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.18 (+0.09/-0.08) and
the cutoff energy, parameterized as Epeak, is 138.0 (+19.6/-14.4) keV.

The event fluence (10-1000 keV) in this time interval is
(9.25 +/- 0.52)E-06 erg/cm^2. The 1s peak photon flux measured
starting from T0+5.44 s in the 10-1000 keV band
is 5.8 +/- 0.3 ph/s/cm^2.

We note that this event is in the direction of SGR 1830-0645 
(K.L. Page et al. 2020, GCN 28594). While we cannot conclusively rule out 
an association with SGR 1830-0645, the GBM spectrum and time history 
are suggestive of a long GRB and not a Magnetar transient. 
Analysis is ongoing to confirm the source.

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: GRB201013A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28607
SUBJECT: GRB 201013A: Swift detection of a burst
DATE:    20/10/13 04:01:49 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

K. L. Page (U Leicester), S. D. Barthelmy (GSFC),
N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and
A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 03:46:30 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201013A (trigger=999948).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 107.388, +57.036 which is 
   RA(J2000) = 07h 09m 33s
   Dec(J2000) = +57d 02' 09"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 15 sec.  The peak count rate
was ~29000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 03:47:39.9 UT, 69.3 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 107.3945, 57.0347 which
is equivalent to:
   RA(J2000)  = 07h 09m 34.69s
   Dec(J2000) = +57d 02' 05.0"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 13 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 does not constrain the column density. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 73 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
0.05. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 
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: GRB201013A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28608
SUBJECT: GRB 201013A: Enhanced Swift-XRT position
DATE:    20/10/13 08:40:14 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 2464 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 201013A, 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 = 107.39425, +57.03422 which is equivalent
to:

RA (J2000): 07h 09m 34.62s
Dec (J2000): +57d 02' 03.2"

with an uncertainty of 1.9 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: GRB201010A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28610
SUBJECT: SGR 1830-0645: Swift/UVOT Upper Limits
DATE:    20/10/13 14:20:18 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

Paul Kuin (UCL-MSSL) and Kim Page (U.Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of SGR 1830-0645/
GRB 201010 71 s after the BAT trigger (Page et al., GCN Circ. 28594).
This field is crowded with sources. Near the XRT position
(Osborne et al. GCN Circ. 28596) we find two sources which were
both observed not to vary within our measuring accuracy of 0.07 mag.
Hence, no optical afterglow consistent with the XRT position
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            71          221          147         >17.6
u_FC               284          534          246         >18.1
white               71          757          186         >17.6
v                  614         5462          216         >16.4
b                  540          733           39         >17.6
u                  284         6049          434         >18.0
w1                 664         5872          216         >18.6
m2                 639         5667          216         >19.7
w2                 590         5257          216         >19.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.78 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB201013A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28611
SUBJECT: GRB 201013A: Swift-XRT refined Analysis
DATE:    20/10/13 16:49:45 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (ASDC),
V. D'Elia (ASDC), B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp
(PSU), J.P. Osborne (U. Leicester) and K.L. Page report on behalf of
the Swift-XRT team:

We have analysed 6.3 ks of XRT data for GRB 201013A (Page et al. GCN
Circ. 28607), from 89 s to 41.3 ks after the  BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Beardmore et al. (GCN Circ. 28608).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.86 (+/-0.03).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.08 (+0.30, -0.29). The
best-fitting absorption column is  4.8 (+/-0.8) x 10^22 cm^-2, in
excess of the Galactic value of 5.4 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 8.0 x 10^-11 (2.4 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.8 (+/-0.8) x 10^22 cm^-2
Galactic foreground: 5.4 x 10^20 cm^-2
Excess significance: 10.4 sigma
Photon index:      2.08 (+0.30, -0.29)

If the light curve continues to decay with a power-law decay index of
0.86, the count rate at T+24 hours will be 0.012 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.4 x
10^-13 (2.8 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/00999948.

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


GRB_name: GRB201013A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28612
SUBJECT: Swift GRB 201013A: Global MASTER-Net observations report 
DATE:    20/10/13 18:12:10 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

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




MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 201013A ( K. L. Page et al., GCN 28607) errorbox  51437 sec after notice time and 51478 sec after trigger time at 2020-10-13 18:04:29 UT, with upper limit up to  18.1 mag. The observations began at zenith distance = 73 deg. The sun  altitude  is -33.0 deg. 

The galactic latitude b = 25 deg., longitude l = 160 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1460562

We obtain a following upper limits.  

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

   51569 |      MASTER-Tavrida |   C |   180 | 18.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201013A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28613
SUBJECT: GRB 201013A: Swift/UVOT Upper Limits
DATE:    20/10/13 19:41:14 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) 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 201013A 74 s after the BAT trigger 
(Page et al., GCN Circ. 28607).
There is a bright optical source (USNO B1.0 1470-0207304) 0.5 arcsec from the enhanced XRT position 
(Beardmore et al. GCN Circ. 28608). The magnitudes measured at this position by UVOT are consistent 
with those catalogued and thus we do not detect any evidence of an afterglow candidate.
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            74          223          147         >16.8
u_FC               286          535          246         >16.7
white               74         1712          412         >16.8
v                  616         1763          136         >16.2
b                  541         1686          117         >16.6
u                  286         1662          343         >16.7
w1                 665         1804          127         >16.6
m2                 640         1611           58         >16.7
w2                 591         1738          136         >17.1

The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of 
E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB201013A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28614
SUBJECT: GRB 201013A: Swift-BAT refined analysis
DATE:    20/10/13 21:21:05 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 201013A (trigger #999948)
(Page et al., GCN Circ. 28607).  The BAT ground-calculated position is
RA, Dec = 107.392, 57.031 deg which is
   RA(J2000)  =  07h 09m 34.1s
   Dec(J2000) = +57d 01' 52.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.

The mask-weighted light curve shows a double-peaked structure that
starts at ~T-1 s and ends at ~T+10 s. The two main peaks occur at
~T+0.5 s and ~T+6.5 s, respectively. T90 (15-350 keV) is 7.36 +- 0.18 sec
(estimated error including systematics).

The time-averaged spectrum from T-0.85 to T+9.64 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.22 +- 0.04.  The fluence in the 15-150 keV band is
6.7 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from
T-0.05 sec in the 15-150 keV band is 24.6 +- 0.7 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/999948/BA/


GRB_name: GRB201013A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28615
SUBJECT: GRB 201013A: FRAM-ORM possible afterglow candidate
DATE:    20/10/13 22:47:15 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek,
Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza
(Institute of Physics, Prague, CZ)

report:

The 25cm robotic telescope FRAM-ORM at La Palma (Spain) reacted robotically
to the alert of GRB201013A (Page et al GCNC 28607), obtaining a series of
20 s unfiltered images starting at 03:47:01.3 UT, i.e. 31.3s post trigger.

There is a relatively bright star (R~16.3) within the errorbox of the XRT
localization. With the relatively coarse resolution of the 25 cm telescope,
direct detection of a faint object within the XRT errorbox is impossible.

We performed aperture photometry of the star. There seems to be an excess
flux of ~3.5 sigma by ~ 570 s post trigger. This is when optical afterglows
often show maxima in their
lightcurves.

We also performed image subtraction of a sum of four images obtained at the
time of the detected peak and twelve latest images of the series. The
resulting frame contains a very
weak residual towards the position of the X-ray afterglow from the star
center.

We therefore conclude that there is a slight possibility of an afterglow
peaking at R~17.0, which was outshined by a nearby star of R~16.3.


GRB_name: GRB201013A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28618
SUBJECT: GRB 201013A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/10/14 10:11:51 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

T. Tamura (Kanagawa U),
A. Yoshida, T. Sakamoto, V. Pal'shin, 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 (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The Swift GRB 201013A (Page et al., GCN Circ. 28607, Laha et al.,
GCN Circ. 28614; https://gcn.gsfc.nasa.gov/other/201013A.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 03:46:29.773 UTC
on 13 October 2020 (http://cgbm.calet.jp/cgbm_trigger/flight/1286595863/).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a double-peaked structure which starts
at T+0.5 sec and ends at T+7.5 sec. The T90 and T50 durations measured
by the SGM data are 6.4 +- 0.4 sec and 1.9 +- 0.6 sec (40-1000 keV),
respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1286595863/

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


GRB_name: GRB201013A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28620
SUBJECT: GRB 201013A: AstroSat CZTI detection
DATE:    20/10/14 16:05:33 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed detection of a long GRB 201013A, which was also detected by Swift (Page K. et al., GCN #28607), Swift-XRT (Beardmore A. et al., GCN #28608), Global MASTER-Net (Lipunov V. et al., GCN #28612), Swift/UVOT (Breeveld A. et al., GCN #28613), Swift-BAT (Laha S. et al., GCN #28614), FRAM-ORM (Jelinek M. et al., GCN #28615) and CALET (Tamura T. et al., GCN #28618).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-13 03:46:32.000 UT. The measured peak count rate associated with the burst is 631 +/- 39 cts/s above the background in the combined data of four quadrants, with a total of 3054 +/- 43 cts. The local mean background count rate was  586 +/- 17 cts/s. Using cumulative rates, we measure a T90 of 11.08 +/- 0.03 s. 

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-13 03:46:29.500 UT. The measured peak count rate is 1229 +/- 53 cts/s above the background in the combined Veto data of four quadrants, with a total of 4458 +/- 55 cts. The local mean background count rate was 1131 +/- 22  cts/s. We measure a T90 of 11.63 +/- 0.01 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB201013A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28621
SUBJECT: GRB 201013A: TSHAO and AbAO optical observations, afterglow confirmation
DATE:    20/10/14 16:20:40 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI), V. Kim (AFIF, Pulkovo Observatory), 
  R. Ya. Inasaridze (AbAO), M. Krugov (AFIF), A. Volnova (IKI)  report 
on behalf of IKI-GRB-FuN:

We observed the field of Swift GRB 201013A (Page et al., GCN 28607; see 
also detection by CALET Tamura et al, GCN 28618) with  Zeiss-1000(W) 1-m 
telescope of Tien Shan Astronomical Observatory (TSHAO) and  AS-32 
telescope of Abastumani observatory (AbAO) in R-filter. Within  enhanced 
XRT position (Beardmore et al., GCN 28608),   at 1.6 arc seconds from 
the center of the position, we observed  an object mentioned by Jelinek 
et al. (GCN 28615) and  listed at least in the USNO-B.10 and PS1 
catalogs. Aperture photometry of the object are brighter than R2=16.22 
magnitude of the object in USNO-B1.0 1470-0207304   in both our 
observations. Flux subtraction of our photometry and  R2=16.22 result in 
photometry of possible afterglow suggested in earlier observations  by 
FRAM-ORM (Jelinek  et al. GCN 28615). Results of the flux subtraction 
assuming negligible error of R2 presented in USNO-B1.0 are following

  Date,     UT start, T0+   Exp.,  Filter, OT, Err., UL, observatory
                     (mid, days)

2020-10-13 21:44:47 0.79464 22*360 R    19.00 (+0.22 -0.18)  20.0 TSHAO
2020-10-13 23:33:56 0.84197 50* 60 R    19.39 (+0.08 -0.08)  21.3 AbAO

The photometry is based on nearby USNO-B1.0 star
USNO-B1.0_id R2
1470-0207278 14.89

While we cannot definitely detect fading the possible afterglow, the 
brightness of possible afterglow faded significantly between earlier 
(Jelinek  et al. GCN 28615) and our observations.

The cross section profile of the object in our observation at 
Zeiss-1000(W) of TSHAO is differ from point like source. The reason of 
the extended profile might be due to offset of the afterglow from the 
foreground star  or could be due to the object USNO-B1.0 1470-0207304 is 
not the star but a galaxy. In the latter case, USNO-B1.0 may be a small 
neighboring host galaxy GRB 201013A.


GRB_name: GRB201013A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28625
SUBJECT: GRB 201013A: Insight-HXMT/HE detection
DATE:    20/10/15 09:03:21 GMT
FROM:    Y Q Zhang at IHEP  <yqzhang@ihep.ac.cn>

C. Zheng, C. Cai, J. C. Liu, Q. Luo, S. Xiao, 
W. C. Xue, Q. B. Yi, Y. Q. Zhang, Y. Huang, C. K. Li, 
G. Li, X. B. Li, J. Y. Liao, X. Y. Song, S. L. Xiong, C. Z. Liu, 
X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, 
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), 
T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-10-13T03:46:30.200 (T0), Insight-HXMT/HE detected 
GRB 201013A (trigger ID: HEB201013157) in a routine search of the data, 
which also triggered Swift/BAT (Page K. L. et al., GCN #28607) and 
CALET (Tamura T. et al., GCN #28618).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 6.77 s measured from T0+0.23 s. 
The 1-ms peak rate, measured from T0+0.53 s, is 20268 cnts/sec. 
The total counts from this burst is 31971 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB201013157_lc.jpg

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB201014A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28626
SUBJECT: Swift-BAT trigger 1000255: XRT afterglow detection of GRB 201014A
DATE:    20/10/15 09:45:28 GMT
FROM:    Valerio D'Elia at ASDC  <valerio.delia@ssdc.asi.it>

V. Dâ€™Elia (SSDC), E. Ambrosi, A. Dâ€™AÃ¬ (INAF-IASFPA) and P.A. Evans (U. Leicester)
report for the Swift-XRT team:

We have analysed 1.5 ks of XRT data for the Swift trigger 1000255 (Ambrosi et al. GCN Circ. 28623), from 156 s to 5.2 ks after the  BAT trigger. The data are entirely in Photon Counting (PC) mode. We detect a bright (2.2E-1 cts/s), fading, uncatalogued X-ray source at the UVOT-enhanced position:

20.79619, 27.66024 which is equivalent to:

RA (J2000):  01 23 11.09
Dec (J2000): +27 39 36.9

with an uncertainty of 1.8 arcseconds (radius, 90% containment). This location is 3.3 arcminutes from the BAT onboard position, at the margin of the BAT error circle. This position was outside of the central window which is telemetered promptly, hence the source was not seen in the initial real-time analysis

Given that no catalogued X-ray sources are present within 5 arc minutes from the XRT position, we conclude that Swift-BAT trigger 1000255 is not due to noise but indeed is a GRB, and the reported source is the X-ray afterglow of GRB 201014A.

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


GRB_name: GRB201014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28628
SUBJECT: GRB 201014A (Swift trigger =1000255): CrAO/ZTSH optical afterglow discovery
DATE:    20/10/15 12:53:30 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), N. Pankov (HSE), V. Rumyantsev (CrAO),  S. Belkin 
(IKI), A. Volnova (IKI)  report on behalf of larger GRB follow-up 
collaboration:

We observed the field of the GRB 201014A = (trigger=1000255) (Ambrosi et 
al., GCN 28623) with ZTSH 2.6m telescope of CrAO observatory starting on 
Oct. 14 (UT) 23:06:56,  i.e. 18.3 minutes after burst detection.  We 
detect an object at the edge of enhanced XRT afterglow position (Dâ€™Elia 
et al., GCN 28626). The coordinates of the object are (J2000) 01 23 
11.058 +27 39 38.39 with uncertainty of 0.3 arcsec in each 
coordinate.The object is absent in both SDSS DR12 and PS1 catalogues. We 
suggest the object is an optical afterglow GRB 201014A.

Preliminary photometry of the object in a combined image is following

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


2018-10-14 23:06:56  0.021967 R      11*120   21.50   0.15   22.6


The photometry is based on several nearby USNO-B1.0 stars.


GRB_name: GRB201014A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28629
SUBJECT: GRB 201014A: Swift-BAT refined analysis
DATE:    20/10/15 17:09:01 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), E. Ambrosi (INAF-IASFPA),
S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 201014A (trigger #1000255)
(Ambrosi et al., GCN Circ. 28623; D'Elia et al., GCN Circ 28626).
The BAT ground-calculated position is
RA, Dec = 20.834, 27.722 deg which is
   RA(J2000)  =  01h 23m 20.2s
   Dec(J2000) = +27d 43' 19.1"
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a weak pulse that starts at ~T+30 s
and ends at ~T+70 s. T90 (15-350 keV) is 36.2 +- 8.1 sec (estimated
error including systematics).

The time-averaged spectrum from T+30.16 to T+69.84 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 2.55 +- 0.37.  The fluence in the 15-150 keV band
is 3.1 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T+59.44 sec in the 15-150 keV band is 0.3 +- 0.2 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

The ground analysis shows an improved image significance
of 8.2 sigma in 15-350 keV. Also, the temporal and spectral
characteristics are consistent with those of a long GRB.
Therefore, the BAT ground analysis confirms that this is a GRB,
consistent with the conclusion reported in D'Elia et al., GCN Circ 28626.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1000255/BA/


GRB_name: GRB201014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28630
SUBJECT: GRB 201014A: BOOTES-1 and -2 early optical upper limits
DATE:    20/10/15 17:13:22 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC),  C. Perez del Pulgar,  A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:

Following the Swift trigger of GRB 201014A (Ambrosi et al., GCNC 28623), the 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) automatically responded to this event. A series of images were taken starting 22:50:46UT (132 s after trigger) with clear filter. In the co-added 60s exposure image, no soure is detected which down to 20.6 mag at the XRT afterglow position (DElia et al., GCNC 28626).

The 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this event at 22:50:20UT (102 s after trigger). In the co-added of 60 s exposure images, no new source is detected which down to 20.3 mag (clear filter).

These early optical non-detections are consistent with the afterglow magnitude reported by Pozanenko et al. (GCNC 28628).

We thank the staff at INTA-CEDEA and La Mayora for their excellent support.


GRB_name: GRB201015A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28632
SUBJECT: GRB 201015A: Swift detection of a burst
DATE:    20/10/15 22:58:36 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

V. D'Elia (SSDC), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC),
A. D'Ai (INAF-IASFPA), J.D. Gropp (PSU), N. J. Klingler (PSU),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), B. Sbarufatti (PSU) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 22:50:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201015A (trigger=1000452).  Swift did not slew immediately 
to the burst due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 354.343, +53.393 which is 
   RA(J2000) = 23h 37m 22s
   Dec(J2000) = +53d 23' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 10 sec.  The peak count rate
was ~700 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+51.6
minutes. There will be no XRT or UVOT data until this time. 

Burst Advocate for this burst is V. D'Elia (delia AT ssdc.asi.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: GRB201015A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28634
SUBJECT: Swift GRB 201015A: Global MASTER-Net observations report 
DATE:    20/10/15 23:02:53 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

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




MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 201015A ( V. D'Elia et al., GCN 28632) errorbox 88 sec after trigger time at 2020-10-15 22:51:41 UT, with upper limit up to  18.5 mag. The observations began at zenith distance = 33 deg. The sun  altitude  is -50.5 deg. 

The galactic latitude b = -8 deg., longitude l = 112 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1462183

We obtain a following upper limits.  

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

      98 |      MASTER-Tavrida |   C |    20 | 17.8 |        
     123 |      MASTER-Tavrida |   C |    70 | 18.5 |  Coadd 
     138 |      MASTER-Tavrida |   C |    20 | 17.9 |        
     184 |      MASTER-Tavrida |   C |    30 | 18.1 |        
     239 |      MASTER-Tavrida |   C |    40 | 18.3 |        
     305 |      MASTER-Tavrida |   C |    50 | 18.4 |        
     385 |      MASTER-Tavrida |   C |    70 | 18.5 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201015A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28635
SUBJECT: GRB 201015A: Swift-XRT observations
DATE:    20/10/16 00:11:29 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), G. Tagliaferri (INAF-OAB), S. Campana (INAF-OAB),
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester) and D.N. Burrows
(PSU) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 201015A at 23:43:47.2 UT,
3214.1 seconds after the BAT trigger. Using promptly downlinked data we
find a fading, uncatalogued X-ray source located at RA, Dec 354.32067,
53.41460 which is equivalent to:
   RA(J2000)  = 23h 37m 16.96s
   Dec(J2000) = +53d 24' 52.6"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 91 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 consistent with the Galactic value of 3.60
x 10^21 cm^-2 (Willingale et al. 2013). 


GRB_name: GRB201016A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28636
SUBJECT: GRB 201016A: Fermi GBM Final Real-time Localization
DATE:    20/10/16 00:38:14 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 00:27:49 UT on 16 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201016A (trigger 624500874.592646 / 201016019).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 174.3, Dec = -2.0 (J2000 degrees, equivalent to J2000 11h 37m, -2d 00'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 93.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201016019/quicklook/glg_skymap_all_bn201016019.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201016019/quicklook/glg_healpix_all_bn201016019.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201016019/quicklook/glg_lc_medres34_bn201016019.gif


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28637
SUBJECT: GRB 201015A: NOT optical afterglow confirmation
DATE:    20/10/16 01:21:02 GMT
FROM:    Daniele B Malesani at DTU Space  <malesani@space.dtu.dk>

D. B. Malesani (DTU Space), A. de Ugarte Postigo (HETH, IAA/CSIC), T. 
Pursimo (NOT), report on behalf of a larger collaboration:

We observed the field of GRB 201015A (D'Elia et al., GCN 28632) using 
the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Our 
first image was taken at 23:25:12 UT (35 min after the trigger). At the 
location of the afterglow candidate reported by Lipunov et al. (GCN 
28633), also consistent with the XRT position (Kennea et al., GCN 
28635), we detect a source not visible in the Pan-STARRS images of the 
same area. We report for this target the following, refined coordinates:

RA(J2000) = 23:37:16.41
Dec(J2000) = +53:24:56.5

with an uncertainty of 0.3" (calibrated against the Gaia catalog).

Our image was taken with a non-standard, broad filter (~3700-9000 AA), 
and the target is affected by a saturation defect from a star. We cannot 
provide a reliable magnitude at the present time, but a rough estimate 
yields ~19.


GRB_name: GRB201014A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28638
SUBJECT: GRB 201014A: Swift-XRT refined Analysis
DATE:    20/10/16 01:59:34 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows
(PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and
V.Dâ€™Elia report on behalf of the Swift-XRT team:

We have analysed 5.1 ks of XRT data for GRB 201014A (Dâ€™Elia et al.
GCN Circ. 28626), from 176 s to 69.0 ks after the  BAT trigger. The
data comprise 17 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. Using 1385 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 =
20.79619, +27.66024 which is equivalent to:

RA (J2000): 01h 23m 11.09s
Dec(J2000): +27d 39' 36.9"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.8 (+1.7, -0.7), followed by a break at T+360 s to an
alpha of 0.58 (+0.09, -0.07).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.92 (+0.27, -0.24). The
best-fitting absorption column is  1.1 (+0.8, -0.4) x 10^21 cm^-2,
consistent with the Galactic value of 7.9 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 3.5 x 10^-11 (4.3 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.1 (+0.8, -0.4) x 10^21 cm^-2
Galactic foreground: 7.9 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.92 (+0.27, -0.24)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01000255.

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


GRB_name: GRB201015A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28639
SUBJECT: GRB 201015A: GOTO confirmation of afterglow detection
DATE:    20/10/16 03:18:47 GMT
FROM:    Kendall Ackley at Monash University  <kendall.ackley@monash.edu>

K. Ackley (1); D. K. Galloway (1); Y-L Mong (1); M. Dyer (2); J. Lyman (3);
K.
Ulaczyk (3); D. Steeghs (3); V. Dhillon (2); P. O'Brien (4); G. Ramsay
(5); S. Poshyachinda (6); R. Kotak (7); L. Nuttall (8); D. Pollacco
(3); R. Breton (9)
((1) Monash University, (2) University of Sheffield, (3) Warwick
University, (4) University of Leicester, (5) Armagh Observatory &
Planetarium, (6) National Astronomical Research Institute of Thailand,
(7) University of Turku, (8) University of Portsmouth, (9) University
of Manchester)
report on behalf of the GOTO collaboration:

We carried out observations with the Gravitational-wave Optical
Transient Observer (GOTO) on La Palma in response to GRB 201015A
(Swift; D'Elia et al; GCN 28632).

We made a series of 4x90 s exposures using our wide L-band filter
(400-700 nm) covering the Swift XRT error box (Swift; Kennea et al.; GCN
28635),
beginning at 51 minutes after trigger, with midtime of the
first observation 23:41:54.25 UT on 15 October 2020.

Using a difference imaging analysis with recent survey observations of
the same pointings as reference, we detect an uncatalogued source
located at (J2000):
RA 23:37:16.42
Dec +53:24:55.89
confirming the OT reported by MASTER (Lupinov et al.; GCN 28633) and
NOT (Malesani et al.; GCN 28637). We find an equivalent magnitude of
g ~ 20.2 mag based on cross-calibration of our L-band magnitudes
against the ATLAS catalogue.

Observations are continuing.

GOTO is operated at the La Palma observing facilities of the University
of Warwick on behalf of a consortium including the University of
Warwick, Monash University, Armagh Observatory, the University of
Leicester, the University of Sheffield, the National Astronomical
Research Institute of Thailand (NARIT) and the Instituto de Astrofisica
de Canarias (IAC) (https://goto-observatory.org
<https://goto-observatory.org/>)


GRB_name: GRB201016B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28640
SUBJECT: GRB 201016B: Fermi GBM Final Real-time Localization
DATE:    20/10/16 03:26:40 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 03:16:21 UT on 16 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201016B (trigger 624510986.143038 / 201016136).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 8.0, Dec = -31.8 (J2000 degrees, equivalent to J2000 00h 32m, -31d 48'), with a statistical uncertainty of 4.6 degrees.

The angle from the Fermi LAT boresight is 83.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201016136/quicklook/glg_skymap_all_bn201016136.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201016136/quicklook/glg_healpix_all_bn201016136.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201016136/quicklook/glg_lc_medres34_bn201016136.gif


GRB_name: GRB201016A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28641
SUBJECT: GRB 201016A: BALROG localization (Fermi Trigger 624500874 / GRB 201016019)
DATE:    20/10/16 03:30:21 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
624500874 at 00:27:49 on 16 Oct. 2020 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) = 176.6+/-0.1 deg
Decl.(2000.0) = -4.3+/-0.2 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB201016019/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB201016019/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB201016019/json

                        


GRB_name: GRB201016B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28642
SUBJECT: GRB 201016B: BALROG localization (Fermi Trigger 624510986 / GRB 201016136)
DATE:    20/10/16 03:43:16 GMT
FROM:    Jochen Greiner at MPE,Garching  <jcg@mpe.mpg.de>

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

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
624510986 at 03:16:21 on 16 Oct. 2020 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) = 1.9+/-3.5 deg
Decl.(2000.0) = -32.6+/-2.4 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB201016136/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB201016136/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB201016136/json

                        


GRB_name: GRB201016B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28643
SUBJECT: Fermi GRB 201016B: Global MASTER-Net observations report 
DATE:    20/10/16 03:45:24 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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) started inspect of the Fermi GRB 201016B ( Fermi GBM team, GCN 28640) errorbox  559 sec after notice time and 718 sec after trigger time at 2020-10-16 03:28:19 UT, with upper limit up to  19.5 mag. The observations began at zenith distance =  2 deg. The sun  altitude  is -48.2 deg. 

The galactic latitude b = -84 deg., longitude l = 342 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1462348

We obtain a following upper limits.  

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

     748 | 2020-10-16 03:28:19 |         MASTER-OAFA | (00h 30m 50.26s , -29d 26m 27.2s) |   C |    60 | 19.5 |        
     828 | 2020-10-16 03:29:38 |         MASTER-OAFA | (00h 30m 09.35s , -27d 25m 42.9s) |   C |    60 | 19.3 |        
     907 | 2020-10-16 03:30:58 |         MASTER-OAFA | (00h 31m 34.87s , -31d 25m 41.9s) |   C |    60 | 19.4 |        
     986 | 2020-10-16 03:32:17 |         MASTER-OAFA | (00h 29m 43.09s , -25d 26m 20.1s) |   C |    60 | 19.4 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201014A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28644
SUBJECT: GRB 201014A: Swift/UVOT Upper Limits
DATE:    20/10/16 04:29:10 GMT
FROM:    Sam LaPorte at PSU  <sjl5346@psu.edu>

 GRB 201014A: Swift/UVOT Upper Limits

J. D. Gropp (PSU) and E. Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201014A
176 s after the BAT trigger (Ambrosi et al., GCN Circ. 28623) .
No optical afterglow consistent with the XRT position
(D'Elia et al., GCN Circ. 28626)
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

b               3291          3483              38            >19.17
uvm2        7457          7657             196           >19.18
u               3035          7877             275           >19.82
v               3365          7452             235           >19.24
uvw1        3414          7862             216           >19.25
uvw2        3514          7248             216           >19.32
white        2876          7042             382           >21.14

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).

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GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28645
SUBJECT: GRB 201015A: BOOTES-1 early optical afterglow detection
DATE:    20/10/16 05:18:34 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC),  C. Perez del Pulgar,  A. Castellon, I. Carrasco, I. Perez-Garcia, A. Reina (Univ. de Malaga) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:

Following the Swift/BAT trigger of GRB 201015A (D'Elia et al., GCNC 28632), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this burst. A series of images were taken starting on 15 Oct at 22:50:48UT (35 s after trigger). We confirm the OT reported by MASTER (Lipunov et al., GCNC 28633) in our co-added 30x1s clear filter images at a similar epoch (T_mid = 205 s) with 17.0 mag, at a position consistent with the reported Swift/XRT X-ray (Kennea et al., GCNC 28635) and late-time optical afterglows position reported by NOT (Malesani et al., GCNC 28637) and GOTO (Ackley et al., GCNC 28639). Further analysis is ongoing.

We thank the staff at INTA-CEDEA for their excellent support.


GRB_name: GRB201016A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28646
SUBJECT: GRB 201016A: Fermi GBM detection
DATE:    20/10/16 05:23:45 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 00:27:49.59 UT on 16 October 2020, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 201016A (trigger 624500874 / 201016019).

The on-ground calculated location, using the GBM trigger data,
is RA = 174.3, DEC = -2.0 (J2000 degrees, equivalent
to 11h 37m, -2d 00'), with an uncertainty of 1.0 degrees
(radius, 1-sigma containment, statistical only; there is additionally a 
systematic error which we have characterized as a mixture of two Gaussians,
one with a radius of 1.8 degrees (52% contribution) and one with a radius 
of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1] ).

The angle from the Fermi LAT boresight at the GBM trigger time is 93 degrees.

The GBM light curve consists of multiple pulses with a duration (T90)
of about 3 s (50-300 keV). The time-averaged spectrum from
T0+6.3 s to T0+9.4 s is best fit by a Band function with Epeak = 181 +/- 2 keV,
alpha = -0.42 +/- 0.01, and beta = -2.75 +/- 0.03

The event fluence (10-1000 keV) in this time interval is
(9.06 +/- 0.04)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+6.8 s in the 10-1000 keV band
is 267.4 +/- 1.1 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: GRB201015A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28647
SUBJECT: GRB 201015A: Enhanced Swift-XRT position
DATE:    20/10/16 06:48:24 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 1576 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 201015A, 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 = 354.31859, +53.41603 which is equivalent
to:

RA (J2000): 23h 37m 16.46s
Dec (J2000): +53d 24' 57.7"

with an uncertainty of 1.7 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: GRB201008A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28648
SUBJECT: GRB 201008A: Swift-XRT afterglow detection
DATE:    20/10/16 07:33:35 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M.G.
Bernardini (INAF-OAB), E. Ambrosi  (INAF-IASFPA) , M. Capalbi
(INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B.
Sbarufatti (PSU) 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
Fermi/GBM and Swift-BAT/GUANO detected burst GRB 201008A (DeLaunay et
al. GCN Circ. 28583). The observations now extend from T0+47.0 ks to
T0+650.8 ks. 

Of the sources reported by Page et al. (GCN Circ. 28587), "Source 4" is
fading with 3-sigma significance, and is therefore likely the GRB
afterglow.  The position of this source is RA, Dec=161.8588, +46.1019
which is equivalent to:

RA (J2000): 10:47:26.10
Dec(J2000): +46:06:06.9

with an uncertainty of 4.8 arcsec (radius, 90% confidence).  This
position is 4.8 arcmin from the BAT/GUANO position.  The source is
fading with alpha >0.8.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021034.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021034.

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


GRB_name: GRB201015A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28649
SUBJECT: GRB 201015A: Redshift from GTC/OSIRIS
DATE:    20/10/16 09:13:32 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D.A. Kann, M. Blazek, J.F. Agui Fernandez, C. Thoene (all HETH/IAA-CSIC), G. Gomez Velarde (GTC) report:

We observed the afterglow of GRB 201015A (Dâ€™Elia et al. GCN 28632, Lipunov et al. GCN 28633) with the 10.4m GTC telescope, at Roque de los Muchachos Observatory (La Palma, Spain) equipped with OSIRIS. The observation started at 4:07 UT (5.28 hrs after the GRB onset) and consisted of 3x900s with the R1000B grism, covering the range between 3700 and 7800 Ã…. 

The spectrum shows a featureless continuum throughout the full spectral range. However, we do identify emission features superposed on the trace, which we identify as [OIII], [OII], and H-beta at a common redshift of 0.426.

The automatic BAT analysis shows that this is a peculiar short but soft spectrum burst. We encourage follow-up to search for the associated supernova that could confirm the long nature of the burst, or the lack of such a supernova which  would indicate a possible short origin.


GRB_name: GRB201014A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28650
SUBJECT: GRB 201014A: Redshift from GTC/OSIRIS
DATE:    20/10/16 11:04:06 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D.A. Kann, M. Blazek, J.F. Agui Fernandez, C. Thoene (all HETH/IAA-CSIC), G. Gomez Velarde and A. Perez Romero (both GRANTECAN) report:

We observed the afterglow of GRB 201014A (Ambrosi et al. GCN 28623; Dâ€™Elia et al. GCN 28626; Pozanenko et al. GCN 28628) with the 10.4m GTC telescope, at Roque de los Muchachos Observatory (La Palma, Spain) equipped with OSIRIS. The observation started on 16 October 2020 at 5:10 UT (30.36 hrs after the GRB onset) and consisted of 3x1200s with the R1000B grism, covering the range between 3700 and 7800 Ã…. 

The spectrum shows signal redwards of 5150 AA, consistent with the Lyman forest, Lyman alpha, SiII, SiIV, OI, and CII at a common redshift of 4.56, which we identify as the redshift of the GRB.


GRB_name: GRB201016A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28651
SUBJECT: GRB 201016A: AstroSat CZTI detection
DATE:    20/10/16 11:27:57 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed detection of a bright long GRB 201016A, which was also detected by Fermi GBM Final Real-time (GCN #28636), BALROG (Biltzinger B. et al., GCN #28641) and Fermi GBM (Wood J. et al., GCN #28646).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-16 00:27:56.500 UT. The measured peak count rate associated with the burst is 4218 +/- 68 cts/s above the background in the combined data of four quadrants, with a total of 8601 +/- 8 cts. The local mean background count rate was  488 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 2.91 +/- 0.01 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-16 00:27:56.000 UT. The measured peak count rate is 6766 +/- 89 cts/s above the background in the combined Veto data of four quadrants, with a total of 14638 +/- 12 cts. The local mean background count rate was 1422 +/- 1  cts/s. We measure a T90 of 3.05 +/- 0.01 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB201013A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28652
SUBJECT: Konus-Wind observation of GRB 201013A
DATE:    20/10/16 13:12:24 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration, bright GRB201013A
(Swift/BAT detection: Page  et al., GCN 28607; Laha et la., GCN 28614;
CALET Gamma-Ray Burst Monitor detection: Tamura et al., GCN 28618;
AstroSat CZTI detection: Gupta et al., GCN 28620;
Insight-HXMT/HE detection: Zheng et al.,  GCN 28625)
triggered Konus-Wind at T0=13589.476 s UT (03:46:29.476).

The burst light curve shows a double-peaked structure
which starts at ~T0-0.2 s and has a total duration of~11.4 s
The emission is seen up to ~3 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.77(-0.33,+0.37)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.768 s,
of 1.64(-0.26,+0.27)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+9.216 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.79(-0.13,+0.17),
the high energy photon index beta = -2.24(-0.21,+0.15),
the peak energy Ep = 212(-31,+32) keV,
chi2 = 73/65 dof.

The spectrum near the peak count rate
(measured from T0 to T0+1.024 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.49(-0.14,+0.16),
the high energy photon index beta = -2.50(-0.35,+0.20),
the peak energy Ep = 308(-39,+46) keV,
chi2 = 75/57 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB201013_T13589/

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


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28653
SUBJECT: GRB201015A: Nanshan/NEXT early optical observations
DATE:    20/10/16 14:16:04 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

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

We observed the field of GRB 201015A (D'Elia et al., GCN 28632) using 
the NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China. 
Observations automatically started at 22:51:31 UT on 2020-10-15, i.e., 
78 s after the BAT trigger. We obtained 3x40s, 4x60s and 12x90s frames 
in the Sloan r-filter until the sky brightens.

The optical afterglow (e.g., Lipunov et al., GCN 28633; Kennea et al., 
GCN 28635; Malesani et al., GCN 28637; Ackley et al., GCN 28639; Hu et 
al., GCN 28645) is clearly detected in our images. The lightcurve rises 
from r = 18.34 +/- 0.08 at T-mid=98 s to the peak of r = 16.97 +/- 0.03 
at T-mid=226 s, and then decays roughly in a powerlaw with the index of 
alpha ~ 1.2. Photometry is calculated with the Pan-STARRS field.


GRB_name: GRB201014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28654
SUBJECT: GRB 201014A: Lowell Discovery Telescope afterglow imaging
DATE:    20/10/16 14:59:54 GMT
FROM:    Simone Dichiara at UMCP/NASA/GSFC  <dichiara@umd.edu>

S.Dichiara (UMD, NASA-GSFC), S.B. Cenko (NASA-GSFC), E. Troja (UMD,
NASA-GSFC), P. Gatkine (Caltech), J.M. Durbak (UMD), A. Kutyrev (UMD,
NASA-GSFC), S. Veilleux (UMD), report on behalf of a larger
collaboration:

We observed the field of the GRB 201014A (Ambrosi et al., GCN 28623)
using the Large Monolithic Imager (LMI) on the 4.3m Lowell Discovery
Telescope (LDT) at Happy Jack, AZ. Observations started on October 16,
07:08:10 UT (1.35 days after the Swift trigger) taking 4 exposures of
175 s each with SDSS i and SDSS r filters. Observations were taken
at an airmass of about 1.01 and seeing of about 1.7".
We detected the optical transient (Pozanenko et al., GCN 28628; de Ugarte
 Postigo et al, GCN 28650) inside the enhanced XRT position (D'Elia et al.
GCN 28626) measuring the following AB magnitudes: i=22.75 +- 0.07 and
r=24.30 +- 0.12.

Magnitudes are calibrated against the SDSS catalog and not corrected
for Galactic extinction.

The r/i drop-out is consistent with the high-z measured from GTC
(de Ugarte Postigo et al, GCN 28650).

We thank the staff of the Lowell Discovery Telescope and Quanzhi Ye for
assistance with these observations.

[GCN OPS NOTE(18oct2020): Per author's request, the Title "GRB 201014A: Lowell Discovery Telescope upper limits"
was changed to "GRB 201014A: Lowell Discovery Telescope afterglow imaging".]


GRB_name: GRB201014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28655
SUBJECT: GRB 201014A: Nanshan/NEXT optical observations
DATE:    20/10/16 15:18:30 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

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

We observed the field of GRB 201014A (Swift trigger =1000255, Ambrosi et 
al., GCN 28623) using the NEXT-0.6m optical telescope located at 
Nanshan, Xinjiang, China. Observations automatically started at 22:52:30 
UT on 2020-10-14, i.e., 232 s after the BAT trigger, and 3x40s, 4x60s, 
12x90s frames in the Sloan r-filter were obtained.

The optical afterglow (Pozanenko et al., GCN 28628; de Ugarte Postigo et 
al, GCN 28650) inside the enhanced XRT position (D'Elia et al. GCN 
28626) is weakly detected in our stacked image, with r = 20.9 +/- 0.3 at 
T-mid = 0.324 hr after the BAT trigger, calibrated with nearby 
Pan-STARRS stars.


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28656
SUBJECT: GRB 201015A: CrAO/ZTSH optical observations
DATE:    20/10/16 15:31:16 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI),  N. Pankov (HSE), A. Pozanenko (IKI), V. Rumyantsev 
(CrAO),  A. Volnova (IKI)  report on behalf of larger GRB follow-up 
collaboration:

We observed the GRB 201015A  (D'Elia et al., GCN 28632) with ZTSH 2.6m 
telescope of CrAO observatory between Oct. 16 (UT) 01:02:14 -- 02:52:23. 
  The optical afterglow  (e.g., Lipunov et al., GCN 28633; Kennea et 
al., GCN 28635; Malesani et al., GCN 28637; Ackley et al., GCN 28639; Hu 
et al., GCN 28645; Zhu et al., GCN 28653) at redshift z=0.426 (de Ugarte 
Postigo et al., GCN 28649) is clearly detected in each frame of 120 s 
exposure in R filter.

The exact photometry of the afterglow depends on the underlying object 
visible and presented in PS1 catalogue (i'=19.6), which may be a host 
galaxy (PS1 magnitude i'=19.6). Preliminary photometry of the afterglow 
in a combined image is following

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


2018-10-16 02:19:26  0.15501 R      12*120   20.66   0.05   23.0


The photometry is based on several nearby USNO-B1.0 stars
USNO-B1.0_id R2
1434-0471702 17.51
1434-0471746 18.23


GRB_name: GRB201015A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28658
SUBJECT: GRB 201015A: Swift-BAT refined analysis (a soft short pulse with a tail emission)
DATE:    20/10/16 16:04:58 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), V. D'Elia (SSDC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 201015A (trigger #1000452)
(D'Elia et al., GCN Circ. 28632).  The BAT ground-calculated position is
RA, Dec = 354.310, 53.446 deg which is
   RA(J2000)  =  23h 37m 14.4s
   Dec(J2000) = +53d 26' 45.0"
with an uncertainty of 2.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.

The mask-weighted light curve shows a short-soft structure with several
overlapping pulses that start at ~T0 and end at ~T+1 s, followed by
a weak-soft tail that lasts till ~T+10 s. T90 (15-350 keV)
is 9.78 +- 3.47 sec (estimated error including systematics).

The time-averaged spectrum from T+0.02 to T+10.35 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 3.03 +- 0.68.  The fluence in the 15-150 keV band
is 2.0 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured
from T+0.08 sec in the 15-150 keV band is 1.8 +- 0.4 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

The BAT spectrum of this event does not appear to be a short hard burst.
However, the quickly fading X-ray and optical afterglows are
consistent with those from a short GRB.

If this is a short GRB, this is one of the softest short bursts
detected by BAT (based on a sample with constrained spectral fits
from the 3rd BAT GRB catalog; Lien & Sakamoto et al. 2016).
Other BAT-detected short GRBs with similar softness include
GRB190326A and GRB140622A. GRB190326A has an ambiguous
origin due to an observing constraint, but late time XRT/UVOT
followup observations suggest that the source is more consistent
with a GRB (Sbarufatti et al., GCN Circ. 24129). GRB140622A was
classified to be a short GRB because the XRT light curve is
consistent with the normal behavior of a short burst
(Sakamoto et al. GCN Circ. 16438; Burrows et al. GCN Circ. 16439).

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1000452/BA/


GRB_name: GRB201015A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28659
SUBJECT: MAGIC observations of GRB 201015A: hint of very high energy gamma-ray signal
DATE:    20/10/16 16:48:37 GMT
FROM:    Oscar Blanch at MAGIC Collaboration  <blanch@ifae.es>

O.Blanch (IFAE-BIST Barcelona), M. Gaug (UAB Barcelona), K. Noda (ICRR University of Tokyo),
A. Berti (INFN Torino), E. Moretti (IFAE-BIST Barcelona), D. Miceli (University of Udine and INFN Trieste),
P. Gliwny (University of Lodz) S. Ubach (UAB Barcelona), B. Schleicher (University of Wuerzburg),
M. Cerruti (University of Barcelona) and A. Stamerra (INAF Rome) on behalf of the MAGIC collaboration
report: 

On October 15, 2020, the MAGIC telescopes observed GRB 201015A following the Swift-BAT trigger (Dâ€™Elia et al., GCN 28632).
MAGIC started observations under good conditions about 40 seconds after the initial Swift trigger, revealing a hint of signal
with significance >3 sigma in the very high energy band. Refined off-line analyses of the data are ongoing.

Further MAGIC observations on GRB 201015A are planned in the coming night. We strongly encourage follow-up
observations by other instruments at all wavelengths.

The MAGIC point of contact for this burst is O. Blanch (blanch@ifae.es). Burst Advocate for this burst is
M. Gaug (Markus.Gaug@uab.cat)

MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes
located at the Observatory Roque de los Muchachos on the Canary island
La Palma, Spain, and designed to perform gamma-ray astronomy in the energy
range from 50 GeV to greater than 50 TeV.


-- 
AvÃ­s -
Aviso - Legal Notice - (LOPD) - http://legal.ifae.es 
<http://legal.ifae.es/>


GRB_name: GRB201015A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28660
SUBJECT: GRB 201015A: Swift-XRT refined Analysis
DATE:    20/10/16 17:26:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), J. D. Gropp (PSU), J.A. Kennea (PSU), A.
Tohuvavohu (U. Toronto), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB) and V.
D'Elia report on behalf of the Swift-XRT team:

We have analysed 7.2 ks of XRT data for GRB 201015A (D'Elia et al. GCN
Circ. 28632), from 3.2 ks to 57.3 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN Circ. 28647).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.49 (+0.24, -0.21).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+/-0.4). The
best-fitting absorption column is  2.3 (+4.6, -2.3) x 10^21 cm^-2, at a
redshift of 0.426, in addition to the Galactic value of 3.6 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 4.0 x
10^-11 (7.7 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 3.6 x 10^21 cm^-2
Intrinsic column:    2.3 (+4.6, -2.3) x 10^21 cm^-2 at z=0.426
Photon index:      2.2 (+/-0.4)

If the light curve continues to decay with a power-law decay index of
1.49, the count rate at T+24 hours will be 10.0 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.0 x
10^-14 (7.7 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01000452.

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


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28661
SUBJECT: GRB 201015A: redshift confirmation
DATE:    20/10/16 18:15:26 GMT
FROM:    Daniele B Malesani at DTU Space  <malesani@space.dtu.dk>

L. Izzo (DARK/NBI), D. B. Malesani (DTU Space), Z.P. Zhu (NAO/CAS, 
HUST), D. Xu (NAO/CAS), A. de Ugarte Postigo (HETH, IAA-CSIC), T. 
Pursimo, report on behalf of a larger collaboration:

We observed the optical counterpart of GRB 201015A (D'Elia et al., GCN 
28632; Lipunov et al., GCN 28634) with the Nordic Optical Telescope, 
equipped with the ALFOSC spectrograph. Spectroscopic observations 
started on 2020 Oct 15.978 UT (38 min after the GRB trigger) and 
consisted of four 900-s exposures with grism #4, covering the wavelength 
range 3800-9400 AA.

A trace is visible across the full spectral range. In the blue part, 
weak absorption features are detected which can be interpreted as Mg II, 
Mg I and Ca II at z = 0.423. Faint emission lines are also detected at a 
consistent redshift, identified as [O II] and Halpha. Our data allow 
thus to confirm the redshift value reported by de Ugarte Postigo et al. 
(GCN 28649) using the GTC. We note that the detection of absorption 
features sets a firm lower limit to the GRB redshift, excluding a chance 
superposition with a background galaxy.

This work made use of the GRBspec database grbspec.iaa.es.


GRB_name: GRB201015A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28662
SUBJECT: GRB 201015A: Swift/UVOT Detection
DATE:    20/10/16 20:49:02 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and V. D'Elia (SSDC)

report on behalf of the Swift/UVOT team:



The Swift/UVOT began settled observations of the field of GRB 201015A

3217 s after the BAT trigger (D'Elia et al., GCN Circ. 28632).

A weak source consistent with the optical position

(Malesani et al. GCN Circ. 28637)

is detected in the initial UVOT exposures.



Preliminary detections and 3-sigma upper limits using the UVOT photometric system

(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:



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



white             3217         3367          147         20.69 +/- 0.28

white             4402         4602          197         20.33 +/- 0.16

v                 3375         4949          331        >19.3

b                 4197         4397          197         20.47 +/- 0.33

u                 3991         4191          197        >19.7

w1                3786         3986          197        >19.3

m2                3579         3779          197        >18.8

w2                4608         4808          197        >19.4



The magnitudes in the table are not corrected for the Galactic extinction

due to the reddening of E(B-V) = 0.34 in the direction of the burst

(Schlegel et al. 1998).


GRB_name: GRB201015A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28663
SUBJECT: Fermi GBM Sub-Threshold Detection of GRB 201015A
DATE:    20/10/16 21:25:33 GMT
FROM:    Cori Fletcher at USRA  <cfletcher@usra.edu>

C. Fletcher (USRA) and P. Veres (UAH) report on behalf of the Fermi-GBM Team:

Swift-BAT detected GRB 201015A at 22:50:13 UT (GCN 28632). There was no
Fermi-GBM onboard trigger around the event.

An automated, blind search for short gamma-ray bursts below the onboard
triggering threshold in Fermi-GBM identified no counterparts.

The GBM targeted search [1], the most sensitive, coherent search for
GRB-like signals was run from +/-30 s around the BAT trigger time. A transient source was
identified whose most significant timescale according to the automated search is 1.024 s,
with a log likelihood ratio of 76 and a location consistent with the Swift-BAT event.

The time-averaged spectrum from T0-0.256 s to T0+0.896 s is adequately fit by a
Band function with Epeak = 14 +/- 6 keV, alpha = -1.0 (fixed), and beta = -2.40
+/- 0.21. Because the peak energy is close to the low energy threshold of GBM,
the low energy photon index is unconstrained. We fix it to the median value of
the GBM GRB sample, however it has no significant effect on the values for Epeak and beta.
The event fluence (10-1000 keV) in this time interval is(2.25 +/- 0.38)E-07 erg/cm^2.
T0 here is 2020-10-15T22:50:13.22 UT = 624495018.22 (MET)


[1] Goldstein et al. 2019 arXiv:1903.12597


GRB_name: GRB201015A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28664
SUBJECT: GRB 201015A: FRAM-ORM afterglow detection
DATE:    20/10/17 06:24:03 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek,
Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza
(Institute of Physics, Prague, CZ)

report:

The 25cm robotic telescope FRAM-ORM at La Palma (Spain)
reacted robotically to the alert of GRB201015A (D'Elia
et al GCNC 28632), obtaining a series of 20 s unfiltered
images starting at 22:50:50.8 UT, i.e. 37.6s post trigger.

We clearly detect the source reported by other telescopes
(Lipunov et al. GCN 28633, Malesani et al GCN 28637, Ackley
et al GCN 28639 and others). As reported before, the
brightness of the object reaches a maximum about 5 minutes
after the trigger with R ~ 16.5 and then decays until the
end of our dataset 2.4 h after the trigger.


GRB_name: GRB201017A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28665
SUBJECT: GRB 201017A: Fermi GBM Final Real-time Localization
DATE:    20/10/17 09:56:54 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 09:46:32 UT on 17 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201017A (trigger 624620797.629664 / 201017407).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 21.7, Dec = 63.5 (J2000 degrees, equivalent to J2000 01h 26m, 63d 30'), with a statistical uncertainty of 7.3 degrees.

The angle from the Fermi LAT boresight is 100.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201017407/quicklook/glg_skymap_all_bn201017407.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201017407/quicklook/glg_healpix_all_bn201017407.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201017407/quicklook/glg_lc_medres34_bn201017407.gif


GRB_name: GRB201017A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28666
SUBJECT: GRB 201017A: Swift detection of a burst
DATE:    20/10/17 10:03:23 GMT
FROM:    Boris Sbarufatti at PSU  <bxs60@psu.edu>

A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC),
J.D. Gropp (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), T. Sakamoto (AGU) and B. Sbarufatti (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 09:46:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201017A (trigger=1000613).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 36.633, +66.673 which is 
   RA(J2000) = 02h 26m 32s
   Dec(J2000) = +66d 40' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of at least 10 sec. Data from ~T+10 s to
~T+100 s are currently unavailable. There might be additional 
burst emission during this interval. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 09:48:15.1 UT, 103.8 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 36.6186,
66.6787 which is equivalent to:
   RA(J2000)  = 02h 26m 28.45s
   Dec(J2000) = +66d 40' 43.4"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 29 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 consistent with the Galactic value of 5.70
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 106 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
1.20. 

Burst Advocate for this burst is A. D'Ai (antonino.dai AT 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: GRB201017A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28667
SUBJECT: Swift GRB 201017A: Global MASTER-Net observations report 
DATE:    20/10/17 11:58:14 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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) was pointed to the Swift GRB 201017A ( A. D'Ai et al., GCN 28666) errorbox  7302 sec after notice time and 7410 sec after trigger time at 2020-10-17 11:50:02 UT, with upper limit up to  19.1 mag. Observations started at twilight.  The observations began at zenith distance = 44 deg. The sun  altitude  is -16.4 deg. 

The galactic latitude b =  6 deg., longitude l = 132 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1463193

We obtain a following upper limits.  

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

    7501 |        MASTER-Tunka |   C |   180 | 19.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28668
SUBJECT: GRB 201015A: classification as long GRB
DATE:    20/10/17 12:55:23 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

P. Minaev (IKI) and A. Pozanenko (IKI)  report on behalf of larger GRB 
follow-up collaboration:

We analyzed GRB 201015A detected by Swift (D'Elia et al., GCN 28632) 
using GBM/Fermi spectral data  (Fletcher et al., GCN 28663) and redshift 
of z = 0.426 (de Ugarte Postigo et al., GCN 28649; Izzo et al., GCN 
28661). GRB 201015A has a low luminosity, Eiso = (1.1 +/- 0.2)*10^50 
erg, and well consistent with the Ep,i â€“ Eiso correlation (Amati 
relation) for type II (long) bursts, see [1] for details and Figure at

http://grb.rssi.ru/GRB201015A/GRB201015A_Epi_Eiso.png

The position of the burst is within 1-sigma confidence area of the 
cluster of type II (long) bursts on the EH â€“ T90,i diagram (see [2] for 
details), indicating strong association with type II bursts, see Figure at

http://grb.rssi.ru/GRB201015A/GRB201015A_EH_T90i.png

We encourage follow-up optical observations to search for associated 
supernova.

[1] - Minaev et al., MNRAS, 492, 1919, 2020
[2] - Minaev et al., arXiv:2008.12752


GRB_name: GRB201017B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28669
SUBJECT: Trigger 1000631: Swift detection of Cen X-3
DATE:    20/10/17 13:49:49 GMT
FROM:    Boris Sbarufatti at PSU  <bxs60@psu.edu>

V. D'Elia (SSDC) and B. Sbarufatti (PSU) report on behalf of the Neil
Gehrels Swift Observatory Team:

At 13:13:50 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201017B (trigger=1000631).  Swift did not slew to the source. 
The BAT on-board calculated location is 
RA, Dec 170.233, -60.614 which is 
   RA(J2000) = 11h 20m 56s
   Dec(J2000) = -60d 36' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure.  The peak count rate was ~1265 counts/sec (15-350 keV), 
at ~6 sec after the trigger. 


GRB_name: GRB201017A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28670
SUBJECT: GRB 201017A: Xinglong TNT upper limit
DATE:    20/10/17 13:56:51 GMT
FROM:    Liping Xin at NAOC, SVOM  <xlp@nao.cas.cn>



GRB_name: GRB201017A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28671
SUBJECT: GRB 201017A: Enhanced Swift-XRT position
DATE:    20/10/17 14:08:46 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 1488 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 201017A, 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 = 36.62010, +66.67877 which is equivalent
to:

RA (J2000): 02h 26m 28.82s
Dec (J2000): +66d 40' 43.6"

with an uncertainty of 2.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB201017A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28672
SUBJECT: GRB 201017A: Xinglong TNT upper limit
DATE:    20/10/17 14:11:41 GMT
FROM:    Liping Xin at NAOC, SVOM  <xlp@nao.cas.cn>

L. P. Xin (NAOC), X. F. Wang(THU),  Y. L. Qiu(NAOC), J. Y. Wei(NAOC),  J. Wang(GXU),  
L. H. Li (NAOC),  C. Wu(NAOC),  E. W. Liang(GXU), X. H. Han (NAOC)and J. S. Deng(NAOC)report:

We began to observe GRB 201017A ( A. D'Ai et al., GCN 28666) 
with Xinglong TNT telescope, China, at 11:10:24.8 (UT), 17th. Otc. 2020, 
about 84 min after the burst, 

10  x 300 sec R band images were obtained. 
No any new source was detected in the XRT errorbox ( A. D'Ai et al., GCN 28666)  
down to the limit magnitude of 19.5 mag in R band for any single image.
The brightness is calibrated to the USNO B1.0 R2 mag.

More analysis are still continuing. 

We acknowledge the excellent support from Xinglong staff Sen Liu. 

The message may be cited.


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28673
SUBJECT: GRB 201015A: Assy and Mondy optical observations
DATE:    20/10/17 15:56:12 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI), 
E. Klunko (ISTP), M. Krugov (AFIF), N. Pankov (HSE), A. Volnova (IKI) 
report on behalf of IKI GRB FuN:

We observed GRB 201015A  (D'Elia et al., GCN 28632) with AZT-33IK 
telescope of Mondy observatory in R-filter starting on Oct. 16 (UT) 
13:42:54 and with AZT-20  telescope  of Assy-Turgen observatory starting 
on Oct. 16 (UT) 14:51:35  in  g',r',i'-filters.  The optical afterglow 
(e.g., Lipunov et al., GCN 28633; Kennea et al., GCN 28635; Malesani et 
al., GCN 28637; Ackley et al., GCN 28639; Hu et al., GCN 28645; Zhu et 
al., GCN 28653) at redshift z=0.426 (de Ugarte Postigo et al., GCN 
28649; Izzo et al., GCN 28661) is detected in stacked images in each filter.

Preliminary photometry of the afterglow is following

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

2020-10-16 13:42:54   0.64075     R      30*120 21.70 0.25  22.0
2020-10-16 14:51:35   0.68081     r'(AB) 36*60  21.85 0.14  23.5
2020-10-16 15:02:53   0.68796     g'(AB) 36*60  22.10 0.10  23.7

The photometry is based on the nearby stars of PanSTARRS-PS1 catalog.
RA, DEC, g, r, i
23:37:17.49934 +53:24:05.6357 18.6327 17.7832 17.4125
23:37:21.06032 +53:24:57.1308 19.4472 18.4947 18.0340


GRB_name: GRB201015A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28674
SUBJECT: GRB 201015A NUTTelA-TAO / BSTI Early Measurements (Preliminary)
DATE:    20/10/18 00:01:47 GMT
FROM:    Bruce Grossan at LBNL/UCB SSL  <Bruce_Grossan@lbl.gov>

B. Grossan (UCB, NU) , Z. Maksut (NU), A. Kim (NU), M. Krugov (FAI), G. F. Smoot (HKUST, UCB, NU), E. Linder (UCB, NU), report on behalf of the Energetic Cosmos Laboratory:

The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) pointed at GRB201015A on receipt of an automated GCN / BAT position alert. We report measurements made with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32,14) instrument  ***during commissioning phase*** and we note cautions with these measurements below.

Calibration with bright Pan-STARRS catalog I stars on our images, for our standard SDSS filters yields, without color corrections, the following photometric values for the OT:

tc-t0(s) g'(mag)    r'(mag)    i'(mag)
-------- -------    --------   ------------
73.2    UL17.8     17.79      17.67
103.2   UL17.8     18.16      17.86
157.6   17.91      16.81      16.96
202.6   17.76      16.63      16.75
247.6   17.94      16.86      16.85
292.6   17.89      17.29      16.87
337.6   17.76      17.02      17.01
382.6   18.21      17.31      17.05
427.6   18.07      17.49      17.16
472.6   18.08      17.56      17.29
517.6   18.31      17.60      17.48
562.6  18.14      17.90      17.66
607.6   18.61      18.00      17.49
652.6   UL18.2     18.13      17.85
697.6   UL18.2     18.37      18.00
742.6   UL18.2     18.53      18.02
787.6   UL18.2     18.45      18.06
832.6   UL18.2     18.41      18.34
877.6   UL18.2     18.71      UL17.9
922.6   UL18.2     18.85      18.21
967.6   UL18.2     UL18.2     18.26
1012.6  UL18.2     UL18.2     UL17.8
1057.6  UL18.2     UL18.2     UL17.8
1102.6  UL18.2     UL18.2     UL17.8
1147.6  UL18.2     UL18.2     UL17.8
1192.6  UL18.2     UL18.3     UL17.8

UL = 5 sigma upper limit
Uncertainties are estimated at ~ 0.1 mag for r',i'; unfortunately at this time we have indications of errors ~ 0.15 mag for g'. 
tc-t0 = trigger time minus image center time. We have not yet established the accurracy of our times. 
The first two co-adds are 30 s in duration; the rest are 45 s. 

The peak in r' at ~200 s is roughly consistent with that of other observers (e.g. see Dong Xu, 2020, GCN 28653), but for precise comparisons see cautionary notes below.  

These measurements are likely among the earliest multi-channel simultaneous optical measurements of GRBs. We encourage additional measurements at all wavelengths to add to these data. 

We caution the reader that the BSTI instrument is in commissioning phase, with known imperfections, and we have not extensively tested our results, e.g. against other simultaneous measurements, or near our detection limits. Please also note that the times are approximate. We anticipate additional refinement and improvement in analysis in 15-30 days posted at http://ecl.nu.edu.kz/gamma-ray-burst/grb201015A. 

----------------------------------
UCB = University of California, Berkeley, USA
NU = Nazarbayev University, Nur-Sultan, Kazakhstan
HKUST = Hong Kong University of Science and Technology
FAI = Fesenkov Astrophysical Institute, Kazakhstan 

The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.


GRB_name: GRB201017A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28675
SUBJECT: GRB 201017A: Fermi GBM detection
DATE:    20/10/18 00:40:30 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076@uah.edu>

S. Poolakkil (UAH), C. Meegan (UAH) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 09:46:32.63 UT on 17 October 2020, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 201017A(trigger 624620797 / 201017407),
which was also detected by the Swift/BAT (A. D'Ai et al. 2020, GCN 28666).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 98
degrees.

The GBM light curve consists of a single peak followed by some
extended emission with a duration (T90) of about 9 s (50-300 keV).
The time-averaged spectrum from T0-4.09 s to T0+5.12 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.20 +/- 0.17 and
the cutoff energy, parameterized as Epeak, is 144 +/- 35 keV.

The event fluence (10-1000 keV) in this time interval is
(1.402 +/- 0.166)E-06 erg/cm^2. The 1-sec peak photon flux
measured starting from T0-0.89 s in the 10-1000 keV band
is 2.9 +/- 0.3 ph/s/cm^2.

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

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


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28676
SUBJECT: GRB 201015A: MMT afterglow imaging
DATE:    20/10/18 03:28:43 GMT
FROM:    Jillian Rastinejad at Northwestern Univ.  <jillianrastinejad2024@u.northwestern.edu>

J. Rastinejad, K. Paterson, C. D. Kilpatrick and W. Fong (Northwestern) report:

''We observed the location of Swift GRB 201015A (D'Elia et al., GCN 28632; Markwardt et al., GCN 28658) with the Binospec imager and spectrograph mounted on the MMT 6.5-meter telescope on Mount Hopkins, Arizona. We obtain 6x120-sec imaging in the i-band and 9x120-sec imaging in the z-band at mid-times of 2020 October 17.365 (1.41 days post-burst) and 2020 October 17.342 (1.39 days post-burst), respectively. Within the XRT position (Evans et al.  GCN 28647), we detect the previously reported optical afterglow (Lipunov et al. GCN 28633; Malesani et al; GCN 28637, Hu et al.; GCN 28645, Zhu et al.; GCN 28653; Belkin et al. GCN 28656; Jelinek et al., GCN 28664; Belkin et al., GCN 28673). Calibrated to PS1, we measure i = 22.2 +/- 0.1 mag and z = 21.9 +/- 0.1 mag (AB system and not corrected for Galactic extinction in the direction of the burst).

In addition to the afterglow, emission extending directly to the southwest of the afterglow position is weakly detected in both bands, at around RA(J2000) = 23:37:16.35, Dec(J2000)=+53:24:55.7. Given its proximity to the afterglow, this may be the host galaxy of GRB 201015A; however our imaging cannot resolve the afterglow from this extended emission. We also detect the brighter galaxy, previously mentioned in Belkin et al. (GCN 28656) and also detected in archival PS1 imaging at an offset of 2.3'' from the afterglow position (Malesani et al., GCN 28637). Given the large offset from the afterglow (13 kpc at z=0.42; de Ugarte Postigo et al., GCN 28649, Izzo et al., GCN 28661), we consider that this source is less likely to be related to the GRB.

Further observations are planned. We thank Skyler Self and Ben Weiner at the MMT for the rapid scheduling and execution of these observations.''


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28677
SUBJECT: GRB 201015A: Xinglong-2.16m optical observations
DATE:    20/10/18 06:29:12 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Z.P. Zhu (NAOC, HUST), X. Liu, S.Y. Fu, D. Xu (NAOC) report:

We observed the field of GRB 201015A (D'Elia et al., GCN 28632; Kennea 
et al., GCN 28635) using the Xinglong-2.16m telescope equipped with the 
BFOSC. Observations were carried out starting at 10:35:46 UT on 
2020-10-16 (i.e., about 11.2 hr after the BAT trigger), and 13x300s 
R-band frames were obtained.

The GRB optical afterglow (e.g., Lipunov et al., GCN 28633; Malesani et 
al., GCN 28637; Ackley et al., GCN 28639; Hu et al., GCN 28645; Zhu et 
al., GCN 28653; Belkin et al., GCN 28673; Jelinek et al., GCN 28664; 
Marshall et al., GCN 28662; Belkin et al., GCN 28656; Grossan et al., 
GCN 28674) is weakly detected in our stacked image, with R = 22.0 +/- 
0.3 at T-mid=12.10 hr, calibrated with the nearby Pan-STARRS field.

We acknowledge the support of the staff of the Xinglong-2.16m telescope, 
in particular J. Zheng and A.Y. Zhou.


GRB_name: GRB201017A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28678
SUBJECT: GRB 201017A: Swift-XRT refined Analysis
DATE:    20/10/18 10:03:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 3.5 ks of XRT data for GRB 201017A (D'Ai et al. GCN
Circ. 28666), from 112 s to 23.0 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Goad et al. (GCN Circ. 28671).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.97 (+0.10, -0.08).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.3 (+0.5, -0.4). The
best-fitting absorption column is  1.6 (+0.6, -0.5) x 10^22 cm^-2, in
excess of the Galactic value of 5.7 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 4.8 x 10^-11 (1.3 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.6 (+0.6, -0.5) x 10^22 cm^-2
Galactic foreground: 5.7 x 10^21 cm^-2
Excess significance: 3.6 sigma
Photon index:      2.3 (+0.5, -0.4)

If the light curve continues to decay with a power-law decay index of
0.97, the count rate at T+24 hours will be 1.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.3 x
10^-14 (2.3 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/01000613.

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


GRB_name: GRB201017A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28679
SUBJECT: GRB 201017A: Assy and Mondy optical observations, possible afterglow detection
DATE:    20/10/18 10:36:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI), 
E. Klunko (ISTP), M. Krugov (AFIF), N. Pankov (HSE), A. Volnova (IKI) 
report on behalf of IKI GRB FuN:

We observed the filed of GRB 201017A  (Fermi GBM Team, GCN 28665; D'Ai 
et al., GCN 28666; Poolakkil et al., GCN 28675) with AZT-33IK telescope 
of Mondy observatory in R-filter starting on Oct. 17 (UT) 14:56:22 and 
with AZT-20  telescope  of Assy-Turgen observatory starting on Oct. 17 
(UT) 14:15:45  in  r' -filter.  At the edge of enhanced Swift-XRT 
position (Goad et al., GCN 28671) we marginally detected the object 
which is absent in any Pan-STARRS images and PS1 catalog. Position of 
the object is (J2000) 02:26:28.31  +66:40:44.74 with uncertainty of 0.5" 
in each coordinate.

Preliminary photometry of the afterglow candidate  is following

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

2020-10-17 14:15:45  0.2043    r'(AB) 50*60   22.9 0.3   23.2 (AZT-20)
2020-10-17 14:56:22  0.2362    R      30*120  n/d  n/d   21.8 (AZT-33IK)


The photometry is based on the nearby stars of PanSTARRS-PS1 catalog.
RA DEC r
02:26:33.94915 +66:39:38.3372 16.1111
02:26:39.68479 +66:38:36.3089 17.4493


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28680
SUBJECT: GRB 201015A: HCT optical photometric follow-up
DATE:    20/10/18 15:11:04 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), D. K. Sahu (IIA), R. Gupta (ARIES), V. Shenoy (IITB), B.
Kumar (ARIES), S. Kiran (IIA), G. C. Anupama (IIA), V. Bhalerao (IITB),
S.B. Pandey (ARIES), S. Barway (IIA), report on behalf of the HCT team:

We observed GRB 201015A reported by Swift-BAT (V. D'Elia et al., GCN
28632;  also see: V. Lipunov et al., GCN 28633; J.A. Kennea et al., GCN
28635; D. B. Malesani et al., GCN 28637; K. Ackley et al., GCN 28639; Y.-D.
Hu et al., GCN 28645; P.A. Evans et al., GCN 28647; A. de Ugarte Postigo et
al., GCN 28649; Z.P. Zhu et al., GCN 28653; S. Belkin et al., GCN 28656; C.
B. Markwardt et al., GCN 28658; A. D'Ai et al., GCN 28660; L. Izzo et al.,
GCN 28661; F. E. Marshall et al., GCN 28662; C. Fletcher et al., GCN
28663;  Martin Jelinek and Jan Strobl et al., GCN 28664; P. Minaev et al.,
GCN 28668; S. Belkin et al., GCN 28673; B. Grossan et al., GCN 28674; J.
Rastinejad et al., GCN 28676;  Z.P. Zhu et al., GCN 28677) with 2.0 m
Himalayan Chandra Telescope (HCT). The field was observed in the V and Rc
filter starting at 2020-10-16T17:54:14.936 UT i.e. ~19 hrs after the event
detection by Swift-BAT. We obtained 9 x 60 sec in Rc and 120 x 9 in the V
band. We clearly detected the source in the stacked image.


We obtained the following photometric results:-

------------------------------------------------------------------

 JD(Mean) | Filter | Mag | Total exposure (sec) |

------------------------------------------------------------------

 2459139.250567 | V  | 21.56  +/-  0.1  |  60 x 9

 2459139.262356 | Rc | 21.33  +/-  0.04 | 120 x 9

------------------------------------------------------------------

These observations were carried out under the ToO program HCT-2020-C3-P6.
We thank HCT staff for conducting the observations.


GRB_name: GRB201015A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28681
SUBJECT: GRB 201015A: GROWTH-India Telescope (GIT) upper limit
DATE:    20/10/18 19:03:03 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), U. Stanzin(IAO), V. Bhalerao (IITB), G. C. Anupama (IIA),
S. Barway (IIA) report on behalf of the GROWTH-India collaboration:

We observed GRB 201015A reported by Swift-BAT (V. D'Elia et al., GCN
28632;  also see: V. Lipunov et al., GCN 28633; J.A. Kennea et al., GCN
28635; D. B. Malesani et al., GCN 28637; K. Ackley et al., GCN 28639; Y.-D.
Hu et al., GCN 28645; P.A. Evans et al., GCN 28647; A. de Ugarte Postigo et
al., GCN 28649; Z.P. Zhu et al., GCN 28653; S. Belkin et al., GCN 28656; C.
B. Markwardt et al., GCN 28658; A. D'Ai et al., GCN 28660; L. Izzo et al.,
GCN 28661; F. E. Marshall et al., GCN 28662; C. Fletcher et al., GCN
28663;  Martin Jelinek and Jan Strobl et al., GCN 28664; P. Minaev et al.,
GCN 28668; S. Belkin et al., GCN 28673; B. Grossan et al., GCN 28674; J.
Rastinejad et al., GCN 28676;  Z.P. Zhu et al., GCN 28677, H. Kumar et al.,
GCN 28680) with 0.7m GROWTH-India Telescope (GIT). The field was observed
in the SDSS râ€™ filter starting at 2020-10-16T20:21:44.41 UT i.e. ~ 21.5 hrs
after the event detection by Swift-BAT. We obtained 10 exposures of 300 sec
each.

We did not find any source in the stacked image up to râ€™ > 20.97 mag (5-sigma)
within the uncertainty region, calibrated against PanSTARRs PS1 data
release (Flewelling et al., 2018).

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 and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB201017A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28682
SUBJECT: GRB 201017A: Swift-BAT refined analysis
DATE:    20/10/18 22:26:32 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  A. D'Ai (INAF-IASFPA),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+823 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 201017A (trigger #1000613)
D'Ai, et al., GCN Circ. 28666).  The BAT ground-calculated position is
RA, Dec = 36.587, 66.663 deg which is 
  RA(J2000)  =  02h 26m 20.9s 
  Dec(J2000) = +66d 39' 45.7" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.

The mask-weighted light curve shows a single, symmetrical main peak from roughly
T-5 sec to T+5 sec, peaking at T+1 sec, followed by weaker emission out to T+20 sec.
T90 (15-350 keV) is 22.08 +- 6.25 sec (estimated error including systematics).

The time-averaged spectrum from T-2.77 to T+23.87 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.48 +- 0.25.  The fluence in the 15-150 keV band is 9.0 +- 1.4 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.87 sec in the 15-150 keV band
is 1.8 +- 0.4 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/1000613/BA/


GRB_name: GRB201019A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28683
SUBJECT: GRB 201019A: Fermi GBM Final Real-time Localization
DATE:    20/10/19 14:12:19 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 11:36:22 UT on 19 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201019A (trigger 624800187.275816 / 201019484).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 163.4, Dec = 14.6 (J2000 degrees, equivalent to J2000 10h 53m, 14d 35'), with a statistical uncertainty of 4.8 degrees.

The angle from the Fermi LAT boresight is 93.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201019484/quicklook/glg_skymap_all_bn201019484.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201019484/quicklook/glg_healpix_all_bn201019484.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201019484/quicklook/glg_lc_medres34_bn201019484.gif


GRB_name: GRB201017A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28684
SUBJECT: GRB 201017A: MITSuME Akeno optical upper limits
DATE:    20/10/19 14:13:28 GMT
FROM:    Ryohei Hosokawa at Tokyo Institute of Technology  <hosokawa@hp.phys.titech.ac.jp>

R. Hosokawa, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa, N.
Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N.
Kawai (TokyoTech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 201017A (The Fermi GBM team, GCN #28665,
A. D'Ai et al., GCN #28666, V. Lipunov et al., GCN #28667, L. P. Xin
et al., GCN #28672, S. Belkin et al., GCN #28679) with the optical
three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi,  Japan.
The observation started at 2020-10-17 12:53:15 UT.(186 min after
trigger) Since some images were heavily affected by bad weather, we
stacked the images with good conditions. We did not find any new point
sources within the enhanced Swift/XRT circle (M. R. Goad et al., GCN
#28671) in all three bands.
We obtained the 5-sigma limits as follows
T0+[min] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
296 17:53:37 9480 g'>20.0,Rc>19.9,Ic>19.2
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used the 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., accepted for publication in PASJ,
https://arxiv.org/abs/2008.11486; https://github.com/MNiwano/Eclaire).


GRB_name: GRB201014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28685
SUBJECT: GRB 201014A: MMT afterglow detection
DATE:    20/10/19 14:17:38 GMT
FROM:    Tanmoy Laskar at U of Bath  <tanmoylaskar@gmail.com>

T. Laskar (University of Bath), K. Paterson, J. Rastinejad, C. D.
Kilpatrick, and W. Fong (Northwestern) report on behalf of a larger
collaboration:

"We observed Swift GRB 201014A (Ambrosi et al., GCN 28623) with Binospec on
the MMT 6.5-meter telescope at Mount Hopkins, Arizona. We obtained
10x120-sec imaging in the i' and z' bands beginning on 2020 October 17 at
08:55:10 UT and 09:31:56 UT, respectively.

Within the XRT position (D'Elia et al., GCN 28626; Perri et al., GCN
28638), we detect the previously reported optical afterglow (Pozanenko et
al., GCN 28628; Zhu et al., GCN 28655). Calibrated to SDSS, we measure i' =
23.3 +/- 0.1 mag and z' = 22.8 +/- 0.1 mag at a mid-time of 2.45 days since
the burst. Magnitudes are in the AB system and are not corrected for
Galactic extinction.

We thank Skyler Self and Ben Weiner at the MMT for the rapid scheduling and
execution of these observations.''


GRB_name: GRB201013A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28686
SUBJECT: GRB 201013A: 3.6m DOT Optical Observations
DATE:    20/10/19 14:42:24 GMT
FROM:    Rahul Gupta at ARIES, India  <rahul@aries.res.in>

R. Gupta (ARIES), A. Kumar (ARIES), Dimple (ARIES), A. Ghosh (ARIES), A. Aryan (ARIES), B. Kumar (ARIES), S. B. Pandey (ARIES), and K. Misra (ARIES) report: 







We observed the XRT localized GRB 201013A detected by Swift-BAT (Beardmore et al., GCN 28608, Page et al., GCN 28607; see also: Laha et al., GCN 28614; Tamura et al., GCN 28618; Gupta et al., GCN 28620; Zheng et al., GCN 28625; Tsvetkova et al., GCN 28652) using the 4Kx4K CCD Imager (Pandey et al. 2018, 2018BSRSL..87...42P) mounted at the axial port of the 3.6m Devasthal Optical Telescope of ARIES Nainital on 13 th and 14 th October 2020. 




Multiple frames having exposure times of 300s each were taken in B and R filters. The measured magnitudes of the bright optical object (USNO-B1.0 1470-0207304) present within the XRT error circle (Beardmore et al., GCN 28608) are consistent with those reported in the USNO-B1.0 catalog (Rmag2=16.22, Bmag2= 16.49) in both the filters. We do not find any evidence of an afterglow candidate in the close vicinity. We obtain the following 3-sigma upper limits. 
Date        UT start     T-T0    Exp.  Filter    OT       Err.     UL     Telescope (days) 
2020-10-13 22:01:55 0.7607 3*300   R        NA         NA   23.2    3.6m DOT 2020-10-13 22:18:14 0.7720 3*300   B        NA         NA   23.5    3.6m DOT The limiting magnitudes quoted are not corrected for the Galactic and Host extinction in the direction of the burst. 3.6m Devasthal Optical Telescope (DOT) is a recently commissioned facility in Northern Himalayan region of India (long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (https://www.aries.res.in). Authors of this GCN circular thankfully acknowledge consistent support from the staff members to run and maintain the 3.6m DOT. This circular may be cited. 


GRB_name: GRB201019A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28687
SUBJECT: GRB 201019A: Fermi GBM Final Real-time Localization
DATE:    20/10/19 14:47:20 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 01:40:02 UT on 19 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201019A (trigger 624764407.642026 / 201019069).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 223.8, Dec = -25.0 (J2000 degrees, equivalent to J2000 14h 55m, -25d 00'), with a statistical uncertainty of 2.3 degrees.

The angle from the Fermi LAT boresight is 89.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201019069/quicklook/glg_skymap_all_bn201019069.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201019069/quicklook/glg_healpix_all_bn201019069.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201019069/quicklook/glg_lc_medres34_bn201019069.gif


GRB_name: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28688
SUBJECT: GRB 201015A: 6 GHz VLA radio afterglow candidate detection
DATE:    20/10/19 14:53:30 GMT
FROM:    Wen-fai Fong at Northwestern U  <wfong@northwestern.edu>

W. Fong, G. Schroeder, J. Rastinejad, and A. Hajela (Northwestern) report:

"We observed the position of GRB 201015A (D'Elia et al., GCN 28632; Markwardt et al., GCN 28658) with the Karl G. Jansky Very Large Array (VLA) beginning on 2020 Oct 17.364 UT (1.41 days post-burst) at a mean frequency of 6 GHz.

We detect a bright, uncatalogued radio source with a flux density of ~0.13 milliJy at the position:

RA(J2000) = 23:37:16.41
Dec(J2000) = +53:24:56.4

with an uncertainty of ~0.3" in each coordinate. This position is consistent with optical afterglow position reported by NOT (Malesani et al., GCN 28637), and the XRT position (Evans et al. GCN 28647). We propose this source as the radio afterglow of GRB 201015A.

We thank the VLA staff for quickly approving and executing these observations."


GRB_name: GRB201014A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28689
SUBJECT: GRB 201014A: 3.6m DOT Optical Observations
DATE:    20/10/19 15:01:21 GMT
FROM:    Amit Kumar at ARIES, India  <amitkundu515@gmail.com>

A. Kumar (ARIES), R. Gupta (ARIES), Dimple (ARIES), A. Ghosh (ARIES), A.
Aryan (ARIES), B. Kumar (ARIES), N Panwar (ARIES), S. B. Pandey (ARIES),

and K. Misra (ARIES) report:


We observed the XRT localized GRB 201014A (Swift trigger =1000255, Ambrosi
et al., GCN 28623; Perri et al., GCN 28638) using the 4Kx4K CCD Imager
(Pandey et al. 2018, 2018BSRSL..87...42P) mounted at axial port of the 3.6m
Devasthal Optical Telescope (DOT) of ARIES Nainital. The observations were
carried out on 2020-10-15 in Bessel R-band (300s X 2 frames) from UT
21:22:35 to 21:32:59 (corresponding to 22.6 hours after the BAT trigger
time).


No new optical source was detected within the Swift XRT enhanced error
circle (see also Pozanenko et al., GCN 28628; de Ugarte Postigo et al, GCN
28650, Zhu et al, GCN 28655). The aperture photometry on the stacked R-band
image was performed and calibrated against the USNO-B1 nearby stars.


The 3-sigma upper limit within the XRT error circle is as follows:


T_start-T0 (hours),       Start UT,            End UT,          Filter,
3-sigma upper limit

-------------------------------------------------------------------------------------------------
22.57, 2020-10-15 UT 21:22:35.8, 2020-10-15 UT  21:32:58.9,  R, >22.5 mag


The limiting magnitude is not corrected for Galactic extinction in the the
direction of the GRB.


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


GRB_name: GRB201019B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28690
SUBJECT: GRB 201019B: Fermi GBM correction to GCN 28687
DATE:    20/10/19 15:15:53 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

GBM trigger 624764407 / 201019069
reported in GCN circular 28687 was incorrectly
labeled as 201019A due to the GCN outage.
This GRB should be referred to as 201019B.


GRB_name: GRB201017A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28691
SUBJECT: GRB 201017A: GROWTH-India optical upper limit
DATE:    20/10/19 15:40:46 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), U. Stanzin(IAO), V. Bhalerao(IITB), G. C. Anupama(IIA), S.
Barway(IIA), report on behalf of the GROWTH-India collaboration:

We observed GRB 201017A reported by Fermi GBM Team (GCN #28665) and Swift-BAT
(A. D'Ai et al., GCN #28666; also see:- V. Lipunov et al., GCN #28667; M.R.
Goad et al., GCN #28671; L. P. Xin et al., GCN #28672; S. Poolakkil et al.,
GCN #28675; J.A. Kennea et al., GCN #28678; S. Belkin et al., GCN #28679) with
0.7m GROWTH-India telescope. The field was observed in the SDSS râ€™ filter
starting at 2020-10-17T12:54:58.41 UT i.e. ~3.13 hrs after the event
detection by Swift-BAT. We did not find any new source in the stacked image
of 10*300 sec exposure, within an uncertainty region of 2.6 arcsec around RA
(J2000): 02h 26m 28.82s, Dec (J2000): +66d 40' 43.6" (GCN 28671) up to râ€™ >
21.01 mag (5-sigma), calibrated against PanSTARRs PS1 data release,
(Flewelling et al., 2018). Assuming a typical power-law decay, this upper
limit is consistent with the râ€™=22.9 mag detection by Belkin et al (GCN #
28679).

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 and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB201017A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28692
SUBJECT: GRB 201017A: SAO RAS optical observations
DATE:    20/10/19 17:43:25 GMT
FROM:    Moskvitin Alexander at SAO RAS  <mosk@sao.ru>

A. S. Moskvitin,  V. N. Aitov (SAO RAS)
on behalf of GRB follow-up team report.

We observed the field of GRB 201017A (Fermi GBM team, GCN #28665;
D'Ai et al., GCN #28666; Poolakkil et al., GCN #28675)
with the 1-m telescope of SAO RAS, Zeiss-1000 + Multi-Mode
Photometer-Polarimeter. We obtained 11 x 300 sec. images in Rc band
on October 17, 22:01:08--23:24:20 UT, t_mid - T0 = 0.5390 days.

We did not detect possible OT reported by Belkin et al. (GCN #28679)
or any sources within the XRT error circle (Goad et al., GCN #28671)
down to a limiting magnitude of 23.0.


GRB_name: GRB201017A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28693
SUBJECT: GRB 201017A iTelescope observation
DATE:    20/10/19 23:35:52 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

K. Hasuda, M. Nakamura, T. Sakamoto (AGU)

We observed the field of GRB 201017A detected by Swift
(D'Ai et al., GCN Circ. 28666) with the iTelescope.Net
(http://www.itelescope.net) T5 (Takahashi Epsilon 250mm) telescope
located at the New Mexico Skies Observatory (NM, USA).
10 images of 60 sec exposures were taken in the Red filter
starting from October 17 on 10:06:37 (UT) about 20.1 min. after
the trigger and stopped on 10:20:44 (UT).

We do not detect the optical afterglow both in the individual
images and the stacked image at the XRT position
(Goad et al., GCN Circ. 28671).  The estimated five sigma
upper limit of the combined image (total exposure of 600 sec)
is ~17.3 using the USNO-B1 catalog.


GRB_name: GRB201016A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28694
SUBJECT: GRB 201016A: Insight-HXMT/HE detection
DATE:    20/10/20 00:41:34 GMT
FROM:    Ce Cai at IHEP  <caice@ihep.ac.cn>

C. Cai, C. Zheng, J. C. Liu, Q. Luo, S. Xiao, 
W. C. Xue, Q. B. Yi, Y. Q. Zhang, Y. Huang, C. K. Li, 
G. Li, X. B. Li, J. Y. Liao, X. Y. Song, S. L. Xiong, C. Z. Liu, 
X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, 
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), 
T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-10-16T00:27:49.500 (T0), Insight-HXMT/HE detected 
GRB 201016A (trigger ID: HEB201016019) in a routine search of the data, 
which also triggered Fermi/GBM (Wood J. et al., GCN #28646) and 
AstroSat/CZTI (Gupta S. et al., GCN #28651).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 3.36 s measured from T0+6.06 s. 
The 1-ms peak rate, measured from T0+7.47 s, is 20372 cnts/sec. 
The total counts from this burst is 57956 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB201016019_lc.jpg

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB201019B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28695
SUBJECT: GRB 201019B: AstroSat CZTI detection
DATE:    20/10/20 05:00:27 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed detection of a long GRB 201019B, which was also detected by Fermi GBM Final Real-time (GCN #28687).

The source was clearly detected in the 40-200 keV energy range. The light curve showed a single peak of emission peaking at 2020-10-19 01:40:11.077 UT. The measured peak count rate associated with the burst is 167 +/- 18 cts/s above the background in the combined data of four quadrants, with a total of 1104 +/- 17 cts. The local mean background count rate was  400 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 14.74 +/- 0.14 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed a single peak of emission peaking at 2020-10-19 01:40:09.503 UT. The measured peak count rate is 276 +/- 33 cts/s above the background in the combined Veto data of four quadrants, with a total of 1552 +/- 36 cts. The local mean background count rate was 1540 +/- 2  cts/s. We measure a T90 of 14.46 +/- 1.62 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB201020A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28696
SUBJECT: GRB 201020A: Swift detection of a burst with an optical counterpart. 
DATE:    20/10/20 05:59:53 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC),
N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC),
K. L. Page (U Leicester), T. Sakamoto (AGU), B. Sbarufatti (PSU) and
A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 05:47:26 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201020A (trigger=1000926).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 261.246, +31.425 which is 
   RA(J2000) = 17h 24m 59s
   Dec(J2000) = +31d 25' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~1800 counts/sec (15-350 keV), at ~17 sec after the trigger. 

The XRT began observing the field at 05:49:47.6 UT, 141.5 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 261.2279,
31.4288 which is equivalent to:
   RA(J2000)  = 17h 24m 54.71s
   Dec(J2000) = +31d 25' 43.8"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 57 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 consistent with the Galactic value of 3.70
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 144 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 17:24:54.67 = 261.22779
  DEC(J2000) = +31:25:42.0  =  31.42834
with a 90%-confidence error radius of about 0.62 arc sec. This position is 5.4
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.14 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.04. 

Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT 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: GRB201020A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28697
SUBJECT: GRB 201020A: MITSuME Akeno optical observation
DATE:    20/10/20 10:25:22 GMT
FROM:    Adachi Ryo at Tokyo Institute of Tech  <adachi@hp.phys.titech.ac.jp>

R. Adachi, R. Hosokawa, K. L. Murata, M. Niwano, F. Ogawa, N.
Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N.
Kawai (TokyoTech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 201020A (E. Ambrosi et al.,GCN Circular
#28696) with the optical three color (g', Rc, and Ic) CCD cameras
attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.
The observation started at 2020-10-20 08:31:00 UT. The first 28 images
were heavily affected by twilight at Akeno Observatory. We detected
the point source at the position consistent with the afterglow
detected previously (E. Ambrosi et al. GCN #28696).
We measured the magnitudes as follows.

T0+[min] MID-UT T-EXP[sec] measured magnitudes
------------------------------------------------------------------------------------------------
196 09:15:39 1260 g'=19.4+/-0.2, Rc=18.4+/-0.1, Ic=18.4+/-0.2
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used GSC2.3 and 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., accepted for publication in PASJ,
https://arxiv.org/abs/2008.11486; https://github.com/MNiwano/Eclaire).


GRB_name: GRB201020A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28698
SUBJECT: GRB 201020A: Enhanced Swift-XRT position
DATE:    20/10/20 13:05:56 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 729 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 201020A, 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 = 261.22827, +31.42804 which is equivalent
to:

RA (J2000): 17h 24m 54.78s
Dec (J2000): +31d 25' 40.9"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB201014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28699
SUBJECT: GRB 201014A: SAO RAS optical observations
DATE:    20/10/20 13:32:15 GMT
FROM:    Moskvitin Alexander at SAO RAS  <mosk@sao.ru>

A. S. Moskvitin,  V. N. Aitov (SAO RAS)
on behalf of GRB follow-up team report.

We observed the field of GRB 201014A, Swift trigger 1000255
(Ambrosi et al., GCN 28623) with the 1-m telescope of SAO RAS,
Zeiss-1000 + Multi-Mode Photometer-Polarimeter.

We obtained 6 x 300 sec. images in Rc band on October 15,
21:11:44--21:43:50, t_mid - T0 = 0.9439 days since trigger.

Inside the enhanced XRT circle (Dâ€™Elia et al., GCN #28626;
Perri et al., GCN #28638) we marginally detected the GRB OT
(Pozanenko et al., GCN #28628; de Ugarte Postigo et al., GCN #28650;
Dichiara et al., GCN #28654; Zhu et al., GCN #28655)
with the brightness of R = 24.0 +/- 0.3 (calibrated against the nearby
SDSS stars, magnitudes converted with the Lupton 2005 equations).

We also obtained 12 x 300 sec. images in Rc band on October 16,
20:55:16--21:59:23, t_mid - T0 = 1.9435 days since trigger.
We did not detect OT down to the limiting magnitude of R_lim = 24.0.


GRB_name: GRB201020A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28700
SUBJECT: Swift GRB 201020A: Global MASTER-Net observations report 
DATE:    20/10/20 16:00:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

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




MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 201020A ( E. Ambrosi et al., GCN 28696) errorbox  35426 sec after notice time and 35521 sec after trigger time at 2020-10-20 15:39:27 UT, with upper limit up to  17.6 mag. Observations started at twilight.  The observations began at zenith distance = 32 deg. The sun  altitude  is -9.4 deg. 

The galactic latitude b = 31 deg., longitude l = 55 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1464820

We obtain a following upper limits.  

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

   35612 |      MASTER-Tavrida |   C |   180 | 16.4 |        
   36013 |      MASTER-Tavrida |   C |   180 | 17.6 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28701
SUBJECT: GRB 201020A: Nanshan/NEXT optical observations
DATE:    20/10/20 16:08:23 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

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

We observed the field of GRB 201020A (Ambrosi et al., GCN 28696) using 
the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 
15x120s frames in the Sloan r-band, starting at 13:48:25 UT on 
2020-10-20, i.e., 8.02 hr after the BAT trigger.

The optical afterglow (Ambrosi et al., GCN 28696; Adachi et al., GCN 
28697) of the burst is clearly detected in our stacked image, with r = 
19.69 +/- 0.06 mag at T_mid = 0.3461 day post-burst, calibrated with 
nearby PS1 stars.


GRB_name: GRB201020B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28702
SUBJECT: GRB 201020B: Fermi GBM Final Real-time Localization
DATE:    20/10/20 17:41:58 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 17:33:54 UT on 20 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201020B (trigger 624908039.329288 / 201020732).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 71.6, Dec = 76.6 (J2000 degrees, equivalent to J2000 04h 46m, 76d 35'), 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/2020/bn201020732/quicklook/glg_skymap_all_bn201020732.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201020732/quicklook/glg_healpix_all_bn201020732.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201020732/quicklook/glg_lc_medres34_bn201020732.gif


GRB_name: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28703
SUBJECT: GRB 201020A: Assy optical observations
DATE:    20/10/20 17:50:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI), V. Kim (AFIF, Pulkovo Observatory), 
   M. Krugov (AFIF), N. Pankov (HSE), A. Volnova (IKI) report on behalf 
of IKI GRB FuN:

We observed the filed of GRB 201020A  (Ambrosi   et al., GCN 28696) with 
AZT-20 telescope of Assy-Turgen observatory starting on (UT) Oct. 20 
(Ut) 14:00:44 (UT)   in  r'-filter.  We clearly detect optical afterglow 
(Ambrosi   et al., GCN 28696;   Adachi et al., GCN 28697; Fu  et al., 
GCN 28701).

Preliminary photometry of the afterglow is following

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

2020-10-20 14:00:44  0.36688  r'(AB) 70*60    19.70 0.03   23.8

The photometry is based on the nearby stars of PanSTARRS-PS1 catalog.
SDSS-DR12_id        r
J172452.73+312623.9 18.459
J172455.96+312344.8 18.057
J172452.57+312302.1 17.618
J172456.76+312315.5 16.876


GRB_name: GRB201020B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28704
SUBJECT: Fermi GRB 201020B: Global MASTER-Net observations report 
DATE:    20/10/20 19:30:28 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(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, O.Ershova 
(Irkutsk State University, API),

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

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




MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 201020B ( Fermi GBM team, GCN 28702) errorbox  116 sec after notice time and 145 sec after trigger time at 2020-10-20 17:36:19 UT, with upper limit up to  19.0 mag. The observations began at zenith distance = 51 deg. The sun  altitude  is -30.3 deg. 

The galactic latitude b = 20 deg., longitude l = 135 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1465475

We obtain a following upper limits.  

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

     160 | 2020-10-20 17:36:19 |      MASTER-Tavrida | (05h 02m 15.44s , +77d 01m 50.6s) |   C |    30 | 18.1 |        
     205 | 2020-10-20 17:36:19 |      MASTER-Tavrida | (05h 02m 15.47s , +77d 01m 50.6s) |   C |   120 | 19.0 |  Coadd 
     216 | 2020-10-20 17:37:09 |      MASTER-Tavrida | (05h 02m 09.73s , +77d 00m 53.6s) |   C |    40 | 18.4 |        
     281 | 2020-10-20 17:38:10 |      MASTER-Tavrida | (05h 02m 16.10s , +77d 01m 14.1s) |   C |    50 | 18.4 |        
     356 | 2020-10-20 17:39:20 |      MASTER-Tavrida | (05h 02m 11.94s , +77d 02m 41.5s) |   C |    60 | 18.5 |        
     447 | 2020-10-20 17:40:41 |      MASTER-Tavrida | (05h 02m 11.08s , +77d 01m 36.7s) |   C |    80 | 18.7 |        
     557 | 2020-10-20 17:42:21 |      MASTER-Tavrida | (04h 48m 10.21s , +76d 33m 54.4s) |   C |   100 | 18.8 |        
     688 | 2020-10-20 17:44:21 |      MASTER-Tavrida | (04h 48m 02.35s , +76d 33m 21.4s) |   C |   120 | 18.9 |        
     843 | 2020-10-20 17:46:42 |      MASTER-Tavrida | (04h 48m 00.81s , +76d 34m 32.4s) |   C |   150 | 18.6 |        
    1029 | 2020-10-20 17:49:33 |      MASTER-Tavrida | (04h 48m 05.91s , +76d 33m 45.8s) |   C |   180 | 18.6 |        
    1230 | 2020-10-20 17:52:54 |      MASTER-Tavrida | (04h 47m 57.59s , +76d 33m 01.0s) |   C |   180 | 18.6 |        
    1431 | 2020-10-20 17:56:14 |      MASTER-Tavrida | (04h 48m 03.67s , +76d 33m 39.0s) |   C |   180 | 18.6 |        
    1631 | 2020-10-20 17:59:35 |      MASTER-Tavrida | (04h 47m 58.81s , +76d 35m 03.2s) |   C |   180 | 18.6 |        
    1772 | 2020-10-20 18:02:56 |      MASTER-Tavrida | (04h 50m 47.49s , +78d 02m 09.0s) |   C |    60 | 18.6 |        
    1852 | 2020-10-20 18:04:16 |      MASTER-Tavrida | (04h 09m 27.94s , +76d 03m 59.8s) |   C |    60 | 18.8 |        
    2013 | 2020-10-20 18:06:57 |      MASTER-Tavrida | (05h 15m 54.03s , +76d 01m 47.7s) |   C |    60 | 18.6 |        
    4831 | 2020-10-20 18:53:55 |      MASTER-Tavrida | (04h 50m 27.27s , +78d 03m 32.9s) |   C |    60 | 18.3 |        
    4912 | 2020-10-20 18:55:16 |      MASTER-Tavrida | (05h 29m 10.28s , +78d 03m 58.0s) |   C |    60 | 18.6 |        
    4992 | 2020-10-20 18:56:36 |      MASTER-Tavrida | (04h 09m 07.67s , +76d 04m 40.5s) |   C |    60 | 18.7 |        
    5073 | 2020-10-20 18:57:56 |      MASTER-Tavrida | (04h 42m 20.94s , +76d 05m 39.8s) |   C |    60 | 18.7 |        
    5233 | 2020-10-20 19:00:37 |      MASTER-Tavrida | (05h 01m 52.50s , +80d 03m 12.9s) |   C |    60 | 18.9 |        
    5315 | 2020-10-20 19:01:58 |      MASTER-Tavrida | (05h 15m 37.60s , +76d 03m 36.6s) |   C |    60 | 18.7 |        
    5814 | 2020-10-20 19:10:18 |      MASTER-Tavrida | (05h 29m 01.57s , +78d 05m 11.8s) |   C |    60 | 18.4 |        
    5895 | 2020-10-20 19:11:38 |      MASTER-Tavrida | (04h 42m 17.73s , +76d 04m 03.6s) |   C |    60 | 18.6 |        
    6260 | 2020-10-20 19:17:44 |      MASTER-Tavrida | (04h 36m 28.16s , +74d 04m 22.2s) |   C |    60 | 18.6 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB201020A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28705
SUBJECT: GRB 201020A: Swift-BAT refined analysis 
DATE:    20/10/20 20:08:10 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

T. Sakamoto (AGU), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC), 
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 201020A (trigger #1000926)
(Ambrosi et al., GCN Circ.28696).  The BAT ground-calculated position is
RA, Dec = 261.239, 31.428 deg which is 
  RA(J2000)  =  17h 24m 57.4s 
  Dec(J2000) = +31d 25' 41.8" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 90%.

The mask-weighted light curve shows a single symmetrical peak starting at ~T+8 sec,
peaking at T+17 sec, and decaying to background by T+26 sec.
T90 (15-350 keV) is 14.17 +- 4.68 sec (estimated error including systematics).

The time-averaged spectrum from T+8.23 to T+30.17 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.25 +- 0.14.  The fluence in the 15-150 keV band is 9.2 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+17.17 sec in the 15-150 keV band
is 2.1 +- 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/1000926/BA/


GRB_name: GRB201020A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28706
SUBJECT: GRB 201020A: Fermi GBM observation
DATE:    20/10/20 21:02:13 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

E. Bissaldi (Politecnico and INFN Bari), C. Malacaria (NASA-MSFC/USRA)
and C. Meegan (UAH) report on behalf of the Fermi GBM Team:

"At 05:47:45.18 UT on 20 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201020A (trigger 624865670 / 201020241),
which was also detected by the Swift/BAT (Ambrosi et al. 2020, GCN 28696).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 66 degrees.

The GBM light curve shows a single emission episode
with a duration (T90) of about 22 s (50-300 keV).
The time-averaged spectrum from T0-10.2s to T0+10.2 s is
best fit by a simple power law function with index -1.83 +/- 0.04.

The event fluence (10-1000 keV) in this time interval is
(2.47 +/- 0.17)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-3.6 s in the 10-1000 keV band
is 3.48 +/- 0.14 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: GRB201020A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28707
SUBJECT: GRB 201020A: Swift-XRT refined Analysis
DATE:    20/10/20 22:29:25 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 6.9 ks of XRT data for GRB 201020A (Ambrosi et al. GCN
Circ. 28696), from 148 s to 35.3 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Osborne et al. (GCN Circ. 28698).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.71 (+/-0.04).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.06 (+0.18, -0.17). The
best-fitting absorption column is  8.6 (+4.4, -3.9) x 10^20 cm^-2, in
excess of the Galactic value of 3.7 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.2 x 10^-11 (3.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      8.6 (+4.4, -3.9) x 10^20 cm^-2
Galactic foreground: 3.7 x 10^20 cm^-2
Excess significance: 2.1 sigma
Photon index:      2.06 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
0.71, the count rate at T+24 hours will be 0.015 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.7 x
10^-13 (5.7 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/01000926.

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


GRB_name: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28708
SUBJECT: GRB 201020A: CrAO/ZTSH optical observations
DATE:    20/10/21 00:03:22 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

N. Pankov (HSE), A. Pozanenko (IKI), V. Rumyantsev (CrAO),  S. Belkin 
(IKI), A. Volnova (IKI)  report on behalf of IKI GRB FuN:

We observed the GRB 201020A  (Ambrosi et al., GCN 28696) with ZTSH 2.6m 
telescope of CrAO observatory starting on Oct. 20 (UT) 16:06:30.  The 
optical afterglow  (Ambrosi et al., GCN 28696;  Adachi et al., GCN 
28697; Fu  et al., GCN 28701;  Belkin  et al., GCN  28703) is clearly 
detected in R filter.
Preliminary photometry of the afterglow in a combined image is following

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

2018-10-20 16:06:30   0.42991 R      30*120   20.00   0.10   21.5

The photometry is based on several nearby USNO-B1.0 (R2) stars.


GRB_name: GRB201020B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28710
SUBJECT: GRB 201020B: Fermi GBM detection
DATE:    20/10/21 01:14:36 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

C. Malacaria (NASA-MSFC/USRA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 17:33:54.33 UT on 20 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201020B (trigger 624908039 / 201020732).
The Fermi GBM Final Real-time Localization was reported in GCN 28702.

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

The GBM light curve shows multiple peaks around
the bright, main peak.
The duration (T90) is about 16 s (50-300 keV).
The time-averaged spectrum from T0-5.1 s to T0+23.5 s is
best fit by a Band function with Epeak = 136.9 +/- 3.4 keV,
alpha = -0.71 +/- 0.02, and beta = -2.20 +/- 0.03

The event fluence (10-1000 keV) in this time interval is
(3.929 +/- 0.040)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+9.4 s in the 10-1000 keV band
is 43.7 +/- 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: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28711
SUBJECT: GRB 201020A: GROWTH-India Telescope optical observations
DATE:    20/10/21 02:17:35 GMT
FROM:    Varun Bhalerao at Indian Inst of Tech  <varunb@iitb.ac.in>

H. Kumar(IITB), J. Stanzin (IIA), V. Bhalerao(IITB), G. C. Anupama(IIA), S. Barway(IIA), report on behalf of the GROWTH-India collaboration:

We followed up GRB 2010210A (E. Ambrosi et al., GCN #28696; also see:- R. Adachi et al., GCN #28697; J.P. Osborne et al., GCN #28698; V. Lipunov et al., GCN #27800, S.Y. Fu et al., GCN #28701; S. Belkin et al., GCN #28703 and T. Pankov et al., GCN #28708) with 0.7m GROWTH-India telescope. We obtained 300-sec exposures in the SDSS râ€™ filter starting at 2020-10-20T13:00:50.42 UT (~7.22 hrs after the burst). We clearly detected uncataloged sources at a position consistent with E. Ambrosi et al., GCN #28696.
Here are the photometric results from GIT observations:-  
------------------------------------------------------------------
 JD (END) | T_end-T0(hrs) | Filter | Mag |
------------------------------------------------------------------
2459143.04576 | 7.31 |  r  |  19.43 +/- 0.06
2459143.04943 | 7.39 |  r  |  19.49 +/- 0.05
2459143.05670 | 7.57 |  r  |  19.52 +/- 0.04
2459143.06046 | 7.66 |  r  |  19.59 +/- 0.04
2459143.06406 | 7.75 |  r  |  19.63 +/- 0.04
2459143.06764 | 7.83 |  r  |  19.65 +/- 0.04
-----------------------------------------------------------------
Combining our photometric results with râ€™ measurements of S.Y. Fu et al., (GCN #28701), S. Belkin et al., (GCN #28703), and T. Pankov et al., (GCN #28708) we conclude that the source is fading with a power-law index of 1.6 +/- 0.2. Given the fast fading, we encourage the follow-up of the source. The magnitudes are 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 and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).


GRB_name: GRB201021A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28712
SUBJECT: GRB 201021A: Fermi GBM Final Real-time Localization
DATE:    20/10/21 02:50:20 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 02:39:55 UT on 21 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201021A (trigger 624940800.414594 / 201021111).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 174.4, Dec = -2.0 (J2000 degrees, equivalent to J2000 11h 37m, -2d 00'), with a statistical uncertainty of 2.5 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/2020/bn201021111/quicklook/glg_skymap_all_bn201021111.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201021111/quicklook/glg_healpix_all_bn201021111.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201021111/quicklook/glg_lc_medres34_bn201021111.gif


GRB_name: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28713
SUBJECT: GRB 201020A: DOAO optical afterglow observations
DATE:    20/10/21 04:51:18 GMT
FROM:    Gregory SungHak Paek at SNU  <shpaek@astro.snu.ac.kr>

Gregory S.H. Paek (CEOU/SNU), Myungshin Im (CEOU/SNU), Taewoo Kim, and
Wonseok Kang (DOAO) on behalf of a larger collaboration

We observed the optical counterpart of GRB 201020A (E. Ambrosi et al., GCN
#28696; R. Adachi et al., GCN #28697; J.P. Osborne et al., GCN #28698; V.
Lipunov et al., GCN #27800, S.Y. Fu et al., GCN #28701; S. Belkin et al.,
GCN #28703, T. Pankov et al., GCN #28708, and H. Kumar et al., GCN #28711)
with the 1-m class telescope in Deokheung Optical Astronomy Observatory
(DOAO). We calibrated flux with PS1 catalog and use AB magnitude system.

---------------------------------------------------------------------
Mid Date[UT] Mid t-t0[days] Filter Exp.time[s] Mag Error
---------------------------------------------------------------------
2020-10-20 10:28:07 0.195 V 300*3 19.361 0.059
2020-10-20 10:33:21 0.199 R 300*3 19.006 0.042
2020-10-20 10:38:35 0.202 I 300*3 18.767 0.039

t0 : 2020-10-20 05:47:26 UT (E. Ambrosi et al., GCN #28696)

The magnitudes are not corrected for galactic extinction.


GRB_name: GRB201020B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28714
SUBJECT: GRB 201020B: AGILE detection
DATE:    20/10/21 08:43:31 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

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

The AGILE Mini-CALorimeter (MCAL) detected GRB 201020B at T0 = 2020-10-20
17:34:03.78 +/- 0.01 s (UTC), reported by Fermi/GBM (GCNs #28702 and
#28710).

The event lasted about 5 s and released a total number of 3250 counts in
the detector (in the 0.4-100 MeV energy range), above an average background
rate of 550 Hz. The MCAL light curve can be found at
http://www.agilescienceapp.it/notices/GRB_069336_525794310.907011.png .

The time-integrated spectrum of the burst can be fitted in the energy range
0.4-20 MeV with a single power-law with ph.ind. = -2.78 -0.03/+0.04,
resulting in a reduced chi-squared of 1.05 (89 d.o.f.) and a fluence of
4.56e-06 ergs/cm^2 (90% confidence level), in the same energy range.

The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and
AntiCoincidence (AC; 50-200 keV) detectors. The event lasted ~27 s and
released a total number of 5856 counts in the SA detector (above a
background rate of 80 Hz); it lasted ~17.5 s and released a total number of
66750 counts in the AC detector (above a background rate of 3670 Hz); it
lasted ~5 s and released a total number of 7506 counts in the MCAL detector
(above a background rate of 1260 Hz). The AGILE ratemeter light curves can
be found at http://www.agilescienceapp.it/notices/GRB_201020B_AGILE_RM.png .

The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. 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: GRB201020B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28716
SUBJECT: GRB 201020B: Fermi-LAT detection 
DATE:    20/10/21 09:28:52 GMT
FROM:    Magnus Axelsson at Stockholm U.  <magaxe@kth.se>

M. Arimoto (Kanazawa Univ.), M. Axelsson (KTH and Stockholm Univ.), F. Longo (University and INFN, Trieste) and E. Bissaldi (INFN and Politecnico Bari) report on behalf of the Fermi-LAT Collaboration:

On October 20, 2020, Fermi-LAT detected high-energy emission from GRB 201020B, which was also detected by Fermi-GBM (trigger 624908039.329288 / 201020732; GCN 28702). The best LAT on-ground location is found to be

RA, Dec = 74.9, 77.0 (degrees, J2000)

with an error radius of 0.21 deg (90% containment, statistical error only). This was 67 deg from the LAT boresight at the time of the GBM trigger:

T0 = 17:33:54.33 UT.

At the time of the trigger, the source was outside the field of view of the LAT. Observations began at T0+2300s and the data from the Fermi-LAT show a significant increase in the event rate in the interval T0+2300 to T0+4600s that is spatially correlated with the GBM emission with high significance. The photon flux above 100 MeV in this time interval is 6.5e-7 +/- 3.3e-7 ph/cm2/s. The estimated photon index above 100 MeV is -1.6+/-0.3.

The highest-energy photon is a 6 GeV event which is observed ~2700 seconds after the GBM trigger.

The Fermi-LAT point of contact for this burst is

Elisabetta Bissaldi (Elisabetta.Bissaldi@ba.infn.it<http://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: GRB201020A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28717
SUBJECT: GRB 201020A: Redshift from GTC/OSIRIS
DATE:    20/10/21 10:30:41 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, 
DARK/NBI), M. Blazek, J. F. Agui Fernandez, C. C. Thoene (all 
HETH/IAA-CSIC), G. Lombardi (GRANTECAN, IAC) and A. Tejero (GRANTECAN) 
report:

We observed the afterglow (Ambrosi et al., GCN#28696; Adachi et al., 
GCN#28697; Fu et al., GCN#28701; Belkin et al., GCN#28703; Pankov et 
al., GCN#28708; Kumar et al., GCN#28711; Paek et al., GCN#28713) of GRB 
201020A (Ambrosi et al., GCN#28696; Sakamoto et al., GCN#28705; Bissaldi 
et al., GCN#28706) with the 10.4m GTC telescope, at Roque de los 
Muchachos Observatory (La Palma, Spain) equipped with OSIRIS. The 
observation started on 20 October 2020 at 20:08 UT (14.34 hrs after the 
GRB onset) and consisted of 4 x 900s with the R1000B grism, covering the 
wavelength range between 3700 and 7800 AA. Observations were taken under 
inclement conditions, with bad seeing and thick clouds passing through.

The spectrum shows a clear continuum, consistent with the Lyman forest, 
Ly-alpha, SiII, OI, CII, SiIV, CIV, FeII, FeII*, and AlII, all at a 
common redshift of z = 2.903, which we identify as the redshift of the 
GRB.


GRB_name: GRB201020B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28718
SUBJECT: GRB 201020B: MASTER bright optical afterglow detection
DATE:    20/10/21 12:19:33 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, A.Kuznetsov, K.Zhirkov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, A.Chasovnikov, 
A.Pozdnyakov, D.Cheryasov(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico FelixAguilar 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),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov, Yu. Sergienko (Blagoveschensk Educational State University)

MASTER-Tavrida wide field robotic-telescope (Lipunov et al. GCN 28704) and 
very wide field cameras observed in alert mode Fermi GRB201020B
(GBM GCN 28703, LAT GCN 28716
https://gcn.gsfc.nasa.gov/other/201020B.gcn3 )

MASTER auto-detection system (Lipunov et al. 2010, Advances in Astronomy, vol. 2010, 30L)
discovered  MASTER OT J050152.74+770406.3
with afterglow light curve at
(RA, Dec2000) = 05h 01m 52.74s +77d 04m 06.3s

with m_OT=13.7 at 2020-10-20.73413 UT.

The OT is seen in 35 images with afterglow behaviour.

We have reference image on 2020-01-02.78682 UT with unfiltered mlim=19.5m.


GRB_name: GRB201020B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28719
SUBJECT: GRB 201020B: Nanshan/NEXT optical afterglow confirmation
DATE:    20/10/21 13:20:48 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

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

We observed the field of GRB 201020B detected by Fermi/GBM, Fermi/LAT, 
and AGILE (Fermi GBM team, GCN 28702; Malacaria et al., GCN 28710; 
Arimoto et al., GCN 28716; Ursi et al., GCN 28714), starting at 12:35:28 
UT on 2020-10-21, i.e., 0.7927 day after the Fermi trigger. Photometry 
has been done in Sloan r-filter with 60s for each exposure, and 
observations are ongoing.

The optical transient reported by MASTER (Lipunov et al., GCN 28718) is 
clearly detected in our single image at improved coordinates

R.A. (J2000) = 5:01:52.80
Dec. (J2000) = +77:04:06.23

with a positional uncertainty of ~0.5 arcsec. It has decayed to m_r = 
19.0 +/- 0.1 at T_mid = 0.7944 day post-trigger, calibrated with nearby 
PS1 stars.

Based on the quick decay behaviour, we confirm that the source is very 
likely the afterglow of the burst.


GRB_name: GRB201020B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28720
SUBJECT: GRB 201020B: Swift ToO observations
DATE:    20/10/21 13:32:38 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 Fermi/LAT GRB 201020B. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021035

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/LAT 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: GRB201015A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28721
SUBJECT: GRB 201015A: SAO RAS optical observations
DATE:    20/10/21 13:48:37 GMT
FROM:    Moskvitin Alexander at SAO RAS  <mosk@sao.ru>

A. S. Moskvitin,  V. N. Aitov (SAO RAS)
on behalf of GRB follow-up team report.

We observed the field of the GRB 201015A (D'Elia et al., GCN #28632)
with the 1-m telescope of SAO RAS, Zeiss-1000 + Multi-Mode
Photometer-Polarimeter on October 16, 19:46:23--20:49:31 UT,
t_mid - T0 = 0.89426 days.

The GRB OT (Lipunov et al., GCN #28633; Malesani et al.,
GCN #28637; Ackley et al., GCN #28639; Hu et al., GCN #28645;
de Ugarte Postigo, GCN #28649; Zhu et al., GCN #28653; Belkin et al.,
GCN #28656; Izzo et al., GCN #28661; Marshall & D'Elia, GCN #28662;
Jelinek et al., GCN #28664; Belkin et al., GCN #28673;
Grossan et al., GCN #28674; Rastinejad et al., GCN #28676;
Zhu et al., GCN #28677; Kumar et al, #GCN 28680) is detected
in the stacked image. Preliminary photometry of the OT
is R = 21.69 +/- 0.05 (based on standards from Belkin et al.,
GCNs #28656, #28673).


GRB_name: GRB201020B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28723
SUBJECT: Konus-Wind detection of GRB 201020B
DATE:    20/10/21 16:18:09 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

The long-duration GRB 201020B
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 28702,
Malacaria & Meegan, GCN Circ. 28710;
AGILE detection: Ursi et al., GCN Circ. 28714;
Fermi-LAT detection: Arimoto et al., GCN Circ. 28716)
triggered Konus-Wind at T0=63237.477 s UT (17:33:57.477).

The burst light curve shows a multipeaked structure
started at ~T0-5.6 s with a total duration of ~53.7 s.
The emission is seen up to ~6 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB201020_T63237/

As observed by Konus-Wind, the burst
had a fluence of 4.72(-0.61,+0.70)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+8.016 s,
of 1.38(-0.25,+0.25)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+50.432 s)
is best fit in the 20 keV - 6 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.12(-0.09,+0.10),
the high energy photon index beta = -2.55(-0.56,+0.26),
the peak energy Ep = 193(-23,+23) keV
(chi2 = 72/97 dof).

The spectrum near the maximum count rate
(measured from T0+7.424 to T0+8.448 s)
is best fit in the 20 keV - 6 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.85(-0.13,+0.14),
the high energy photon index beta = -2.78(-3.16,+0.36),
the peak energy Ep = 259(-35,+44) keV
(chi2 = 41/52 dof).

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


GRB_name: GRB201020B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28725
SUBJECT: GRB 201020B: Mondy optical observations
DATE:    20/10/21 17:09:41 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of  GRB 201020B (Fermi GBM team, GCN 28702; 
Malacaria et al., GCN 28710; Arimoto et al., GCN 28716; Ursi et al., GCN 
28714; Ridnaia et al., GCN 28723) with AZT-33IK telescope of Sayan 
observatory (Mondy) starting on Oct. 21 (UT)  14:20:10. The optical 
transient (Lipunov  et al. GCN 28718; Xu  et al. GCN 28719) is well 
detected in our images in R-filter.

Preliminary photometry of the optical transient in a combined image is 
following

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

2020-10-21 14:20:10   0.88629    R      60*60   18.99 0.03   22.7


The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1670-0037414 16.74
1670-0037586 16.16


GRB_name: GRB201021B
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28726
SUBJECT: GRB 201021B MAXI/GSC detection
DATE:    20/10/21 18:31:15 GMT
FROM:    Satoshi Nakahira at RIKEN  <nakahira@crab.riken.jp>

S. Nakahira (JAXA), M. Serino (AGU), Y. Kawakubo (LSU),
H. Negoro, M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino (Nihon U.), 
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Nishida, K. Komachi, A. Yoshida (AGU), 
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.), 
M. Shidatsu (Ehime U.),
N. Kawai, R. Adachi, M. Niwano (Tokyo Tech), 
Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA), 
Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake, U. Goto, R. Uematsu (Kyoto U.), 
H. Tsunemi (Osaka U.), 
M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.), 
T. Kawamuro (NAOJ), 
K. Yamaoka (Nagoya U.),
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 2020-10-21T16:18:55UT .
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (3.592 deg, -63.535 deg) = (00 14 22, -63 32 05) (J2000)
with a 90% C.L. statistical error of 0.24 deg and an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 212 +- 25 mCrab (4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at UT 14:46 
and in the next transit at 17:51 UT with an upper limit of 20 mCrab for each.


GRB_name: GRB200826A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28727
SUBJECT: GRB200826A: GMOS-N detection of a supernova bump
DATE:    20/10/21 18:40:54 GMT
FROM:    Tomas Ahumada at U. of Maryland  <tahumada@astro.umd.edu>

Tomas Ahumada (UMD), Leo Singer (NASA GSFC), Harsh Kumar (IITB), and Simeon
Reusch (DESY) report on behalf of the ZTF and GROWTH collaborations:

We imaged position of ZTF20abwysqy/AT2020scz (Ahumada et al. GCN 28295),
the afterglow of GRB 200826A (GCN 28284) with the Gemini Multi-Object
Spectrograph (GMOS-N) mounted on the Gemini-North 8-meter telescope on
Mauna Kea, on 2020-09-23 and 2020-10-10.

Each epoch consisted of 14 r- and i- band 200s exposures. We reduced and
co-added the images from each epoch using DRAGONS, a Python-based data
reduction platform provided by the Gemini Observatory. We subtracted the
coadded images of the two epochs using HOTPANTS. A source is detected on
2020-09-23 at the position of the afterglow with i = 23.9 AB mag and r >
23.5 AB mag.

At host galaxy's redshift of z = 0.7481 (GCN 28319) and assuming Planck
2015 cosmological parameters, the absolute magnitude of the GMOS-N
detection is M_i = -19.5 AB mag. At this time, a kilonova would have an
absolute magnitude of M_i >~ -14.5 AB mag whereas a SN1998bw-like supernova
would have an absolute magnitude of M_i ~ -19 AB mag. Since the GMOS-N
detection is consistent with a supernova but not a kilonova, we conclude
that GRB 200826A was powered by a collapsar rather than a neutron star
merger.

We thank the Gemini Observatory Director for awarding this observing time
and the Gemini staff for help with planning and for executing the
observations.
-- 
Tomas Ahumada (he/him)
Ph.D. Student
Department of Astronomy
University of Maryland, College Park
NASA Goddard Space Flight Center, Code 661
B.Sc. Astronomy, Pontificia Universidad CatÃ³lica de Chile


GRB_name: GRB201021C
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28730
SUBJECT: GRB 201021C: Swift detection of a burst with an optical counterpart
DATE:    20/10/21 20:40:16 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), M. G. Bernardini (INAF-OAB),
D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC/CRESST), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), M. J. Moss (GWU), T. Sakamoto (AGU),
T. Sbarrato (INAF-OAB) and B. Sbarufatti (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 20:27:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201021C (trigger=1001130).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 12.550, -55.839 which is 
   RA(J2000) = 00h 50m 12s
   Dec(J2000) = -55d 50' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 25 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 20:29:00.6 UT, 102.0 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 12.53057, -55.86729 which
is equivalent to:
   RA(J2000)  = 00h 50m 07.34s
   Dec(J2000) = -55d 52' 02.2"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 109 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 consistent with the Galactic value of 2.05
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 105 seconds after the BAT trigger. There is a candidate afterglow in
the list of sources generated on-board at
  RA(J2000)  = 00:50:06.85 =  12.52855
  DEC(J2000) = -55:51:56.7  = -55.86576
with a 90%-confidence error radius of about 1.10 arc sec. This position is 2.8
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.19. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.02. 

Burst Advocate for this burst is A. Y. Lien (amy.y.lien 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: GRB201021C
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28733
SUBJECT: GRB 201021C: MASTER optical synchronously observation 
DATE:    20/10/21 21:46:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, A.Kuznetsov,K.Zhirkov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, A.Chasovnikov, A.Pozdnyakov,
V.Topolev, D.Cheryasov(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico FelixAguilar 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),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov, Yu. Sergienko (Blagoveschensk Educational State University)

MASTER-SAAO started GRB 201021C (Lien et al. GCN 28730) observation by
MASTER-II (2x4sq.deg.) in 2020-10-21 20:31:04UT and also detected OT at
Swift-UVOT position (Lien et al. GCN 28730) 
in 2 polarization filters.
MASTER very wide field cameras (Lipunov et al. 2010, Advances in Astronomy, vol.2010, 30L)
observed this GRB _synchronously_  .
Observation and reduction will continue.


GRB_name: GRB201021C
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28736
SUBJECT: GRB 201021C: Enhanced Swift-XRT position
DATE:    20/10/22 01:22:09 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 742 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 201021C, 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 = 12.52888, -55.86549 which is equivalent
to:

RA (J2000): 00h 50m 6.93s
Dec (J2000): -55d 51' 55.8"

with an uncertainty of 1.7 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: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28737
SUBJECT: GRB 201020A: VIRT optical observations
DATE:    20/10/22 02:04:54 GMT
FROM:    Priyadarshini Gokuldass at U. of the Virgin Islands  <priyadass.94@gmail.com>

P. Gokuldass (UVI), R. Strausbaugh (UVI), N. Orange (OrangeWave Innovative
Science, LLC), D. Morris (UVI), A. Cucchiara (UVI/College of Marin) report:

We observed the field of GRB201020A (Ambrosi et al., GCN 28696) with the
0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 10-20-2020 starting at 23:11:52.3 UT (T+17.2
hrs). We performed a series of exposures in R filter with a total exposure
of 3140 s. The weather conditions were clear during the hours of
observation with an average airmass of 2.1.

We find no new source within the enhanced XRT position error circle
(Osborne et al., 28698) and report the following 3-sigma upper limit:

T_mid       ||Exposure     ||Filter      ||Limit
T+18 hrs   ||3140s          ||R            ||>20.6

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

This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR AST
Award 1901296, and NSF HBCU-UP AST Award 1831682. This message can be cited.


GRB_name: GRB201021C
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28739
SUBJECT: GRB 201021C: VLT/X-shooter redshift
DATE:    20/10/22 08:45:59 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

J.-B. Vielfaure (GEPI - Paris Observatory), D. Xu (NAO/CAS), J. Palmerio 
(GEPI - Paris Observatory), P. D'Avanzo (INAF-OAB), D. B. Malesani (DTU Space), 
J. P. U. Fynbo (DAWN/NBI), V. D'Elia (ASI/SSDC), D. A. Kann (HETH/IAA-CSIC) and 
N. R. Tanvir (Univ. Leicester) report on behalf of the Stargate collaboration:

We observed the optical afterglow of GRB 201021C (Lien et al., GCN 
28730; Lipunov et al., GCN 28733) using the ESO VLT UT3 (Melipal) equipped 
with the X-shooter spectrograph. Our spectra cover the wavelength range 3000-21000 AA, 
and consist of 4 exposures by 600 s each. The observation started at 03:29:00 UT on 
2020 Oct 22 (7.02 hr after the GRB).

In a 30 s image taken with the acquisition camera on Oct 22.14 UT, we detect the optical 
afterglow, for which we measure a magnitude r = 19.97 +/- 0.02 (AB, calibrated against 
nearby stars from the SkyMapper catalog; Wolf et al. 2018, PASA, 35, 010).

We clearly detect continuum over the whole X-shooter spectrum.
From detection of multiple absorption features, which we interpret as 
due to Si II, Al II, Al III, Fe II and Mg II, we infer a redshift z = 1.070.
In particular, weak fine structure lines from Fe II* are visible, which 
confirm the association of the absorption system with the GRB. 
We also detect Mg II and Mg I absorption features from an intervening 
system at z = 0.805. 


We acknowledge excellent support from the ESO observing staff in 
Paranal, in particular Bin Yang and Fernando Selman.


GRB_name: GRB201020B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28740
SUBJECT: GRB 201020B: Swift-XRT afterglow detection
DATE:    20/10/22 09:04:39 GMT
FROM:    Paolo D'Avanzo at INAF - OAB  <paolo.davanzo@inaf.it>

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

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 201020B (Arimoto et al. GCN Circ. 28716),
collecting 1.7 ks of Photon Counting (PC) mode data between T0+72.1 ks
and T0+74.3 ks. 

An uncatalogued X-ray source is detected and is above the RASS limit,
and is therefore likely the GRB afterglow. Using 1015 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 = 75.46680, +77.06830 which is equivalent to:

RA (J2000): 05h 01m 52.03s
Dec(J2000): +77d 04' 05.9"

with an uncertainty of 2.0 arcsec (radius, 90% confidence). This
position is 9.6 arcmin from the Fermi/LAT position and consistent with
the optical counterpart detected by MASTER (Lipunov et al. GCN Circ.
28718).  The light curve is consistent with a constant source of mean
count rate 1.5e-01 ct/sec. With the currently available dataset we
cannot constrain the temporal evolution.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+0.4, -0.3). The
best-fitting absorption column is  4.0 (+1.7, -1.4) x 10^21 cm^-2, in
excess of the Galactic value of 1.4 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 3.3 x 10^-11 (5.7 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.0 (+1.7, -1.4) x 10^21 cm^-2
Galactic foreground: 1.4 x 10^21 cm^-2
Excess significance: 3.0 sigma
Photon index:      2.2 (+0.4, -0.3)

The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/ToO_GRBs/00021035/Source1.php.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021035.

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


GRB_name: GRB201014A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28741
SUBJECT: GRB 201014A: 2.0m HCT upper limit
DATE:    20/10/22 10:03:44 GMT
FROM:    Brajesh Kumar at Indian Inst. of Astrophysics  <brajesh.kumar@iiap.res.in>

Brajesh Kumar (ARIES, Nainital), Anirban Dutta, G. C. Anupama, D. K. 
Sahu, Pramod Kumar (IIA, Bengaluru), Amit Kumar, Avinash Singh (ARIES, 
Nainital)

We observed the field of GRB 201014A (Ambrosi et al., GCN 28623, D'Elia 
et al., GCN 28626) with the Himalaya Faint Object Spectrograph and 
Camera (HFOSC) mounted on the 2-m Himalayan Chandra Telescope (IAO, 
Hanle). Three frames (each 300 sec) of the GRB field were obtained in 
the Bessell R-band in the average sky conditions. Preliminary PSF 
photometry on the stacked image was performed and calibrated against 
USNO-B1 catalogue stars. We do not detect any OT candidate (Pozanenko et 
al., GCN 28628, de Ugarte Postigo et al, GCN 28650, Dichiara et al. 
28654, Zhu et al, GCN 28655, Laskar et al. 28685, Kumar et al. 28689, 
Moskvitin et al. 28699) within the enhanced XRT position (Perri et al., 
GCN 28638).

The upper limit in the stacked image is the following:

DATE           UT    Filter Exposure(sec)  Frames  Upper limit (mag)
2020-10-15  15:55:29    R        300         3          21.7

We thank the staff at IAO and CREST for helping with the observations.


GRB_name: GRB201020A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28742
SUBJECT: GRB 201020A: Swift/UVOT Observations
DATE:    20/10/22 12:16:21 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>

M. H. Siegel (PSU) and E. Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201020A
144 s after the BAT trigger (Ambrosi et al., GCN Circ. 28696).
We confirm the fading source initially reported by Ambrosi et al. and
since confirmed by numerous observations (Adachi et al., GCN 
Circ. 28697; Fu  et al., GCN Circ. 28701;  Belkin et al., GCN Circ. 28703,
Pankow et al. GCN Circ. 28708, Kumar et al. GCN Circ. 28711, Paek et al.
GCN Circ. 28713).  The afterglow is not detected in UVOT's NUV filters,
which would be consistent with the redshift of 2.9 reported by Kann et al.
(GCN Circ. 28717).

The preliminary UVOT position is:
   RA  (J2000) =  17:24:54.66 = 261.22773 (deg.)
   Dec (J2000) = +31:25:42.1  =  31.42837 (deg.)
with an estimated uncertainty of 0.44 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 (fc)         145          294          147      18.19+/-0.05
white              583          775           38      19.39+/-0.23
white             9805        10713          885      19.71+/-0.09
white           131168       131712          531            >21.48
v                  632          826           38      17.91+/-0.28
v                21653        22150          485      19.26+/-0.28
v                34473        35292          798      19.86+/-0.29
v               125782       126429          629            >19.99
b                  558          750           38            >19.30
b                22822        23469          630      20.35+/-0.21
b                39219        39998          759      21.05+/-0.36
b               130256       131163          885            >20.60
u (fc)             303          552          245      19.76+/-0.27
u                  706          726           19            >18.42
u                29427        29557          128            >19.69
uvw1               681          876           38            >18.16
uvw1             28521        29420          885            >20.42
uvm2               656          676           19            >17.06
uvm2             27614        28514          885            >20.29
uvw2               608          800           38            >18.04
uvw2             10719        34466         1329            >20.71

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB201020B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28743
SUBJECT: GRB 201020B: Swift/UVOT Detection
DATE:    20/10/22 12:34:19 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201020B 72102 s after the Fermi 
GMB/LAT trigger (Fermi GBM team, GCN Circ. 28702; Malacaria and Meegan, GCN Circ. 28710; Arimoto et 
al., GCN Circ. 28716).
A source consistent with the Master position (Lipunov et al., GCN Circ. 28718), also detected by Xu 
et al., (GCN Circ. 28719), Ridnaia et al. (GCN Circ. 28723), Belkin et al. (GCN Circ. 28723) and 
Sbarufatti et al. (GCN Circ. 28740), is detected in the initial UVOT exposures. We note there is a 
faint USNO-B1.0 source (1670-0037526, Bmag ~21.7) 5.2" away from this position.

Preliminary detections 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            73636        73973          332         19.54 Â± 0.09
v                73979        74316          331         19.30 Â± 0.28
u                72102        72821          708         19.12 Â± 0.11
u   73293       73631      332  19.41 Â± 0.19

The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of 
E(B-V) = 0.15 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB201020A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28744
SUBJECT: Konus-Wind detection of GRB 201020A
DATE:    20/10/22 12:51:04 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

The long-duration GRB 201020A
(Swift-BAT trigger #1000926: Ambrosi et al., GCN 28696;
Sakamoto et al., GCN 28705; T0(BAT)=05:47:26.16 UT;
Fermi-GBM observation: Bissaldi et al., GCN 28706)
was detected by Konus-Wind (KW) in the waiting mode.

The burst light curve shows a single emission episode
with a duration of ~ 15 s.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB201020A/

As observed by Konus-Wind, the burst had a fluence of
1.38(-0.23,0.45)x10^-6 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(BAT)+16.5 s, of 1.34(-0.28,+0.47)x10^-7 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The K-W 3-channel time-integrated spectrum
(from ~T0(BAT)+10.6 s to ~T0(BAT)+25.3 s)
is best described by simple power-law model
with photon index of -2.41(-0.12,+0.17), chi2=0.06/1 dof.

Assuming the redshift z=2.903 (Kann et al., GCN 28717)
and a standard cosmology model with H_0 = 67.3 km/s/Mpc,
Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~2.6x10^52 erg,
and the peak luminosity L_iso is ~1.0x10^52 erg/s.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB201021C
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28745
SUBJECT: GRB 201021C: Swift/UVOT Detection
DATE:    20/10/22 13:16:47 GMT
FROM:    Samantha Oates at MSSL  <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U.Birmingham) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 201021C
105 s after the BAT trigger (Lien et al., GCN Circ. 28730).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 28736)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
 RA  (J2000) =  00:50:06.93 =  12.52886 (deg.)
 Dec (J2000) = -55:51:56.8  = -55.86577 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections 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 (FC)      105          255         147         16.66 +/- 0.03
white              598          617           19         16.22 +/- 0.05
v                    647          667           19         16.49 +/- 0.16
b                    573          593           20         16.80 +/- 0.10 
u  (FC)           317          567         246         15.76 +/- 0.03 
u                    722          742           19         16.06 +/- 0.10
uvm2             672          692           19         16.43 +/- 0.24       
uvw2             623          643           19         16.68 +/- 0.22

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB201020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28747
SUBJECT: GRB 201020A: GROWTH-India Telescope late-time optical upper limit
DATE:    20/10/22 15:21:06 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar (IITB), J. Stanzin (IAO), V. Bhalerao(IITB), G. C. Anupama (IIA),
S. Barway (IIA), report on behalf of the GROWTH-India collaboration:


We observed GRB 201020A reported by Swift-BAT (E. Ambrosi et al., GCN
#28696) with 0.7m GROWTH-India telescope. The field was observed in the
SDSS râ€™ filter with multiple 300-sec exposures. We obtained the following
late time upper limit:
----------------------------------------------------------------------

 JD (mean)| T-T0(hrs) | Filter | Exposure (sec) | Lim_mag (5-sigma) |

----------------------------------------------------------------------

2459144.094375 | 32.47 | râ€™ | 14 * 300 (stacked) | > 21.47 |

----------------------------------------------------------------------

This upper limit is consistent with our best-fit power-law decay from H.
Kumar et al., GCN #28711. Magnitudes are in the AB system and calibrated
against PanSTARRs PS1 data release, (Flewelling et al., 2018).


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 and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB201021C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28748
SUBJECT: GRB 201021C: Fermi GBM detection
DATE:    20/10/22 15:41:24 GMT
FROM:    Stephen Lesage at Fermi-GBM Team  <sjl0014@uah.edu>

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

"At 20:27:21.92 UT on 21 October 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 201021C (trigger 625004846 / 201021852)
which was also detected by the Swift/BAT (A. Y. Lien et al. 2020, GCN
28730).
The Fermi GBM on-ground localization is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is ~59
degrees.

The GBM light curve shows a single bright peak
with a duration (T90) of about 35.3 s (50-300 keV).
The time-averaged spectrum from T0-5.9 s to T0+29.4 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.1 +/- 0.2 and
the cutoff energy, parameterized as Epeak, is 131.1 +/- 28.2 keV.

The event fluence (10-1000 keV) in this time interval is
(1.7 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0-1.9 s in the 10-1000 keV band
is 1.82 +/- 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: GRB201020B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28750
SUBJECT: GRB 201020B: Konkoly Obs. optical detection
DATE:    20/10/22 18:48:16 GMT
FROM:    Jozsef Vinko at Konkoly Observatory  <vinko@konkoly.hu>

J. Vinko (Konkoly/ELTE/U Szeged), A. Pal, L. Kriskovics, R. Szakats, A. Ordasi and K. Vida (Konkoly)
report on behalf of the "Transient Astrophysical Objects" project:

We observed the field of GRB 201020B (Fermi team, GCN 28702; Lipunov et al. GCN 28704;
Malacaria and Meegan, GCN 28710; Ursi et al. 28714; Arimoto et al., GCN 28716;
Lipunov et al., GCN 28718; Xu et al., GCN 28719; Ridnaia et al., GCN 28723;
Belkin et al., GCN 28725; Sbarufatti et al., GCN 28740; Breeveld et al., GCN 28743)
with the 0.8m RC80 robotic telescope at Piszkesteto Mountain Station of Konkoly Observatory
through SDSS r' and i' filters (exposure time 3 x 300 sec per filter)
on 2020 Oct 21.807 UT (MJD 59143.807; 25.8 hours = 92880 s after the trigger).
The frames were tied to PS1-photometry of local stellar sources.
An optical afterglow of the GRB has been detected with the following AB-magnitudes:

r' = 20.869 +/- 2.311 AB mag
i' = 19.368 +/- 0.696 AB mag

which are consistent with previous detections of the fading afterglow.


GRB_name: GRB201020B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28753
SUBJECT: GRB 201020B: GROWTH-India Telescope optical observations
DATE:    20/10/22 20:37:16 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar(IITB), K. Sharma(IITB), J. Stanzin(IAO), V. Bhalerao(IITB), G. C.
Anupama(IIA), S. Barway(IIA), report on behalf of the GROWTH-India
collaboration:


We followed-up GRB 201020B reported by Fermi GBM Team (GCN #28702, also
see: V. Lipunov et. al., GCN #28718; D. Xu et. al., GCN #28719) with 0.7m
GROWTH-India telescope. We obtained 300-sec exposures in the SDSS râ€™ filter
starting at 2020-10-21T14:53:24.42 UT (~ 21.4 hrs after the burst detection
by Fermi-GBM). We clearly detected uncataloged sources at a position
consistent with V. Lipunov et. al., GCN #28718; D. Xu et. al., GCN #28719.

Here are the photometric results from GIT observations:-

------------------------------------------------------------------

 JD (mid) | T_mid-T0(hrs) | Filter | Mag |

------------------------------------------------------------------

2459144.12392 | 21.45 | r | 19.36 +/- 0.07

2459144.12752 | 21.53 | r | 19.49 +/- 0.08

2459144.13110 | 21.62 | r | 19.37 +/- 0.07

2459144.27999 | 25.15 | r | 19.64 +/- 0.02

2459144.30582 | 25.77 | r | 19.79 +/- 0.02

2459144.35140 | 26.86 | r | 19.83 +/- 0.03

2459144.39582 | 27.91 | r | 19.83 +/- 0.03

2459144.42656 | 28.67 | r | 19.89 +/- 0.02

-----------------------------------------------------------------

Combining our photometric results with r band measurements of D. Xu et.
al., GCN #28719, we conclude that the source is fading with a power-law
index of 1.65 +/- 0.21. The magnitudes are calibrated against PanSTARRs PS1
data release, (Flewelling et al., 2018) and not corrected for galactic
extinction. Extrapolating backwards to the epoch of MASTER observations (t0
+ 3.2 min), the expected r magnitude is approximately 8.6, significantly
higher than the measured clear band magnitude of 13.7. This may be
indicative of a break in the afterglow. Further observations are strongly
encouraged.

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 and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB201021C
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28754
SUBJECT: GRB 201021C: Swift-XRT refined Analysis
DATE:    20/10/22 20:40:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 4.3 ks of XRT data for GRB 201021C (Lien et al. GCN
Circ. 28730), from 105 s to 58.8 ks after the  BAT trigger. The data
comprise 62 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Beardmore et al. (GCN Circ. 28736).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.22 (+0.07, -0.06).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.62 (+0.19, -0.16). The
best-fitting absorption column is  5 (+21, -5) x 10^20 cm^-2, at a
redshift of 1.07, in addition to the Galactic value of 2.0 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 4.0 x
10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 2.0 x 10^20 cm^-2
Intrinsic column:    5 (+21, -5) x 10^20 cm^-2 at z=1.07
Photon index:      1.62 (+0.19, -0.16)

If the light curve continues to decay with a power-law decay index of
1.22, the count rate at T+24 hours will be 2.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-13 (1.1 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/01001130.

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


GRB_name: GRB201021C
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28755
SUBJECT: GRB 201021C: Swift-BAT refined analysis
DATE:    20/10/22 22:30:34 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 (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(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 201021C (trigger #1001130)
(Lien, et al., GCN Circ. 28730).  The BAT ground-calculated position is
RA, Dec = 12.503, -55.862 deg which is 
   RA(J2000)  =  00h 50m 00.6s 
   Dec(J2000) = -55d 51' 44.0" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 80%.

The mask-weighted light curve shows a single peak running from ~T-5 sec to 
T+20 sec, with a broad peak around T+3 sec. T90 (15-350 keV) is 24.38 +- 6.76 sec 
(estimated error including systematics).

The time-averaged spectrum from T-4.19 to T+27.95 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.15.  The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-3.62 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/1001130/BA/


GRB_name: GRB201024A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28760
SUBJECT: Swift GRB201024A: Global MASTER-Net OT detection
DATE:    20/10/24 03:09:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, P.Balanutsa,
A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov,
D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

D. Buckley
(South African Astronomical Observatory),

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

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


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

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

MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB201024A (trigger 1001514) 36 sec after notice
time and 66 sec after trigger time at 2020-10-24 02:51:20 UT.
On our first (10s exposure) set we  found 1 optical transient within Swift error-box (ra=125.95 dec=3.35444 r=0.05) brighter than  16.5.

  T-Tmid      Date      Time       Expt.        Ra                Dec         Mag
---------|---------------------|-------|-----------------|-----------------|-----
      229   2020-09-25 21:54:16     40   (08h 23m 48.58s,   +03d 21m 13.8s) 14.9

The 5-sigma upper limit has been about  17mag
The message may be cited.


GRB_name: GRB201024A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28761
SUBJECT: GRB 201024A: Swift detection of a burst with an optical afterglow
DATE:    20/10/24 03:10:12 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

F. E. Marshall (NASA/GSFC), M. G. Bernardini (INAF-OAB),
P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU), N. J. Klingler (PSU),
N. P. M. Kuin (UCL-MSSL), S. Laha (GSFC/UMBC/CRESST),
A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sbarrato (INAF-OAB)
and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels
Swift Observatory Team:

At 02:48:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201024A (trigger=1001514).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 125.948, +3.377 which is 
   RA(J2000) = 08h 23m 47s
   Dec(J2000) = +03d 22' 38"
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 ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 02:50:14.0 UT, 74.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 125.9521,
3.3537 which is equivalent to:
   RA(J2000)  = 08h 23m 48.50s
   Dec(J2000) = +03d 21' 13.4"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 85 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 consistent with the Galactic value of 3.64
x 10^20 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 6.41e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 495 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 08:23:48.55 = 125.95229
  DEC(J2000) = +03:21:14.5  = 3.35403
with a 90%-confidence error radius of about 0.62 arc sec. This position is 0.7
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.85 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03. 

Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.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: GRB201024A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28762
SUBJECT: GRB 201024A: MASTER correction to GCN 28760
DATE:    20/10/24 03:18:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

Due to a typo, the OT datetime data in the table(GCN 28760) was wrong
Here are the correct values

  T-Tmid      Date      Time       Expt.        Ra                Dec         Mag
---------|---------------------|-------|-----------------|-----------------|-----
       66   2020-10-24 02:51:20     10   (08h 23m 48.58s,   +03d 21m 13.8s) 14.9

The OT position is coincident with UVOT and XRT position. The afterglow appears to be fading rapidly.


GRB_name: GRB201024A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28763
SUBJECT: GRB 201024A: BOOTES-2/TELMA early optical observation and 1.5m OSN follow-up
DATE:    20/10/24 04:10:24 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

E. Fernandez-Garcia, Y.-D. Hu, A. J. Castro-Tirado, A. Sota (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC), M.D. Caballero-Garcia and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report:

The 0.6m BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) automatically responded to the Swift trigger of GRB 201024A (Marshall et al. GCNC 28761). A series of images were taken starting on Oct 24 at Oct 02:50:07 UT (~68 s after trigger). A bright optical source is detected on the first image (10s, clear filter) with r= 14.1 mag, at a position consistent with the optical afterglow reported by UVOT/Swift (Marshall et al. GCNC 28761) and MASTER (Lipunov et al. GCNC 28760).

Furthermore, from a deeper image gathered at the 1.5m OSN telescope in Observatorio de Sierra Nevada at 03:16 UT we measure R = 18.9, thus confirming the rapid fading of the optical afterglow brightness as pointed out on GCNC 28762.

Additional observations are ongoing.  We thank the staff at La Mayora and OSN for their excellent support.


GRB_name: GRB201024A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28764
SUBJECT: GRB 201024A: Redshift from GTC/OSIRIS
DATE:    20/10/24 04:28:55 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D. A. Kann, M. Blazek, 
J. F. Agui Fernandez, C. C. Thoene (all HETH/IAA-CSIC), S. Geier, and M. 
Rivero (both GRANTECAN) report:

We observed the afterglow (Lipunov et al., GCN#28760, Marshall et al., 
GCN#28761, Fernandez-Garcia et al., GCN#28763) of GRB 201024A (Marshall 
et al., GCN#28761) with the 10.4m GTC telescope, at Roque de los 
Muchachos Observatory (La Palma, Spain) equipped with OSIRIS. The 
observation started on 24 October 2020 at 03:28:47 UT (0.663 hrs after 
the GRB onset) and consisted of 3 x 900 s with the R1000B grism, 
covering the wavelength range between 3700 and 7800 AA. Observations 
were taken under good conditions but high airmass.

At the afterglow position, a clear source is detected. We measure r' ~ 
19.3 mag (AB) vs. nearby PanSTARRS field stars. This indicates the 
source has faded rapidly vs. the early MASTER/BOOTES detection, as 
Lipunov et al., GCN#28760 and Fernandez-Garcia et al., GCN#28763 stated.

A preliminary reduction of the spectrum shows a clear continuum, with 
MnII, FeII, FeII*, MgII, and MgI absorption lines, as well as the [OII] 
doublet in emission, all at a common redshift of z = 0.999, which we 
identify as the redshift of the GRB.

We furthermore note that there is an underlying galaxy at the OT 
position visible in SDSS and PanSTARRS, at r ~ 21.15 mag. We also see a 
second galaxy offset by a few arcsec in our finding chart.

We thank P. D'Avanzo and L. Izzo for pointing out the galaxy.


GRB_name: GRB201020B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28765
SUBJECT: GRB 201020B: Redshift from GTC/OSIRIS
DATE:    20/10/24 06:29:31 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, 
DARK/NBI), M. Blazek, J. F. Agui Fernandez, C. C. Thoene (all 
HETH/IAA-CSIC), S. Geier, and M. Rivero (both GRANTECAN) report:

We observed the afterglow (Lipunov et al., GCN#28718; Xu et al., 
GCN#28719; Belkin et al., GCN#28725; Breeveld & Lien, GCN#28743; Vinko 
et al., GCN#28750; Kumar et al., GCN#28753) of GRB 201020B (Fermi GBM 
Team, GCN#28702; Fermi GBM detection: Malacaria & Meegan, GCN#28710; 
Fermi LAT detection: Arimoto et al., GCN#28716; AGILE detection: Ursi et 
al., GCN#28714; Konus-Wind detection: Ridnaia et al., GCN#28723) with 
the 10.4m GTC telescope, at Roque de los Muchachos Observatory (La 
Palma, Spain) equipped with OSIRIS. The observation started on 24 
October 2020 at 04:05:16 UT (3.438 days after the GRB trigger, following 
a period of inclement weather) and consisted of 4 x 1200 s with the 
R1000B grism, covering the wavelength range between 3700 and 7800 AA. 
Observations were taken under good conditions.

At the afterglow position, a source is clearly detected. We measure i' ~ 
21.45 mag (AB) vs. a nearby PanSTARRS field star. This represents a 
significant decay compared to the value reported by Vinko et al. 
(GCN#28750). The afterglow is seen to decay with a slope of 1.68, in 
full agreement with Kumar et al. (GCN#28753).

A preliminary reduction of the spectrum shows a clear but featureless 
continuum. There is an emission feature, which we identify as due to the 
[OII]3727 doublet at z = 0.804. Other interpretations (as Hbeta, [OIII] 
or Halpha) would imply other emission lines should be visible, which 
they are not. At the same redshift there could be marginal, weak 
features consistent with FeII, MgII, and MgI. Therefore, we suggest z = 
0.804 as the redshift of the GRB.


GRB_name: GRB201024A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28766
SUBJECT: GRB 201024A: FRAM-ORM afterglow detection
DATE:    20/10/24 08:56:09 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek,
Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza
(Institute of Physics, Prague, CZ)

report:

The 25cm robotic telescope FRAM-ORM at La Palma (Spain)
reacted robotically to the alert of GRB201024A (Marshall
et al GCNC 28761), obtaining a series of 20 s unfiltered
images starting at 02:49:34.4 UT, i.e. 35.3s post trigger.

We clearly detect the source reported by other telescopes
(Lipunov et al. GCN 28760, Fernandez-Garcia et al. GCN 28763,
de Ugarte Postigo et al GCN 28764 and others). As reported
before, the brightness of the object reaches a maximum of
about R(Vega) = 14.0 and then decays relatively steeply with a
power law index alpha = ~1.5.


GRB_name: GRB200901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  28767
SUBJECT: GRB 200901A: FRAM-Auger optical limit
DATE:    20/10/24 08:57:10 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Martin Jelinek, Jan Strobl (ASU CAS Ondrejov, CZ),
Martin Masek, Petr Janecek, Sergey Karpov, Jakub
Jurysek, Jan Ebr, Ronan Cunniffe, Petr Travnicek and
Michael Prouza (Institute of Physics, Prague, CZ)

report:

The 30cm robotic telescope FRAM-Auger in Malargue (Argentina)
reacted robotically to the Swift/BAT alert of GRB200901A
(Simpson et al., GCNC 28335, Burrows et al., GCNC 28336,
Kennea et al., GCNC 28341, and Breeveld et al., GCNC 28342).

The weather was cloudy but as the clouds moved, we could
select some good images, in particular there is a continuous
set of 14 exposures between 4:00 and 4:17 UT, where the
position could be well identified.

We do not detect any new or strongly variable source at or
around the reported X-ray errorbox at single frames or a
combined 14 x 20s R-band image with the exposure mid-time
21.3 min after the initial trigger. The combined exposure has
a limiting magnitude R(Vega) = 17.8, as calibrated against
the Atlas Catalogue.


