GRB 261111A
GCN Circular 46229
Subject
Fermi GRB 261111A: Global MASTER-Net observations report
Date
2026-11-11T19:01:00Z (3 hours ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
D.Buckley (SAAO),
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko,
G.Antipov, A.Sankovich, Yu.Tselik, Ya..Kechin, V.Senik, A.Chasovnikov, K.Labsina (Lomonosov MSU)
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
A.Sosnovskij (Lomonosov MSU)
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory)
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
R.Rebolo (The Instituto de Astrofisica de Canarias)
O.Gress, N.Budnev(ISU)
M. Segura, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA)
MASTER-SAAO robotic telescope [1] located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 261111A ( Fermi GBM team, GCN 46224) errorbox 24042 sec after notice time and 24075 sec after trigger time at 2026-11-11 18:08:23 UT, with upper limit up to 18.9 mag. Observations started at twilight. The observations began at zenith distance = 77 deg. The sun altitude is -12.0 deg.
The galactic latitude b = -36 deg., longitude l = 182 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3532560
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
24105 | 2026-11-11 18:08:23 | MASTER-SAAO | (03h 41m 03.46s , +04d 53m 45.6s) | C | 60 | 17.8 |
24199 | 2026-11-11 18:09:56 | MASTER-SAAO | (03h 41m 00.85s , +04d 55m 28.3s) | C | 60 | 17.9 |
24199 | 2026-11-11 18:09:56 | MASTER-SAAO | (03h 42m 44.93s , +04d 40m 11.4s) | C | 60 | 14.0 |
24292 | 2026-11-11 18:11:29 | MASTER-SAAO | (03h 49m 02.26s , +04d 54m 01.1s) | C | 60 | 17.8 |
24387 | 2026-11-11 18:13:04 | MASTER-SAAO | (03h 41m 43.61s , +06d 48m 32.7s) | C | 60 | 18.1 |
24479 | 2026-11-11 18:14:37 | MASTER-SAAO | (03h 41m 43.19s , +06d 49m 34.1s) | C | 60 | 18.3 |
24573 | 2026-11-11 18:16:11 | MASTER-SAAO | (03h 49m 52.12s , +06d 48m 45.9s) | C | 60 | 18.0 |
24666 | 2026-11-11 18:17:44 | MASTER-SAAO | (03h 49m 45.83s , +06d 47m 47.5s) | C | 60 | 18.3 |
25041 | 2026-11-11 18:23:58 | MASTER-SAAO | (03h 40m 58.87s , +04d 54m 42.0s) | C | 60 | 18.9 |
25041 | 2026-11-11 18:23:58 | MASTER-SAAO | (03h 42m 43.10s , +04d 39m 21.5s) | C | 60 | 17.6 |
25133 | 2026-11-11 18:25:31 | MASTER-SAAO | (03h 40m 59.01s , +04d 55m 42.6s) | C | 60 | 18.9 |
25133 | 2026-11-11 18:25:31 | MASTER-SAAO | (03h 42m 43.23s , +04d 40m 21.4s) | C | 60 | 17.7 |
25227 | 2026-11-11 18:27:05 | MASTER-SAAO | (03h 49m 06.25s , +04d 54m 58.5s) | C | 60 | 18.7 |
25228 | 2026-11-11 18:27:05 | MASTER-SAAO | (03h 50m 50.43s , +04d 39m 37.9s) | C | 60 | 16.8 |
25320 | 2026-11-11 18:28:38 | MASTER-SAAO | (03h 48m 59.04s , +04d 53m 58.6s) | C | 60 | 18.7 |
25320 | 2026-11-11 18:28:38 | MASTER-SAAO | (03h 50m 43.24s , +04d 38m 37.6s) | C | 60 | 17.0 |
25414 | 2026-11-11 18:30:12 | MASTER-SAAO | (03h 41m 49.74s , +06d 47m 54.2s) | C | 60 | 18.5 |
25414 | 2026-11-11 18:30:12 | MASTER-SAAO | (03h 43m 34.27s , +06d 32m 32.0s) | C | 60 | 17.3 |
25508 | 2026-11-11 18:31:45 | MASTER-SAAO | (03h 41m 46.33s , +06d 49m 38.2s) | C | 60 | 18.5 |
25508 | 2026-11-11 18:31:45 | MASTER-SAAO | (03h 43m 30.88s , +06d 34m 15.7s) | C | 60 | 17.4 |
25603 | 2026-11-11 18:33:21 | MASTER-SAAO | (03h 49m 49.77s , +06d 48m 01.9s) | C | 60 | 17.5 |
25603 | 2026-11-11 18:33:21 | MASTER-SAAO | (03h 51m 34.29s , +06d 32m 39.7s) | C | 60 | 15.8 |
25695 | 2026-11-11 18:34:53 | MASTER-SAAO | (03h 49m 51.94s , +06d 49m 37.0s) | C | 60 | 17.9 |
25696 | 2026-11-11 18:34:53 | MASTER-SAAO | (03h 51m 36.47s , +06d 34m 14.5s) | C | 60 | 16.1 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
[1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp.
http : // www.pereplet.ru/lipunov/625.html
GCN Circular 46225
Subject
GRB 261111A: BALROG localization (Fermi Trigger 816089232 / GRB 261111477)
Date
2026-11-11T12:08:38Z (10 hours ago)
From
Jochen Greiner at MPE <jcgrog@mpe.mpg.de>
Via
email
T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
816089232 at 11:27:07 on 11 Nov. 2026 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position is:
RA(2000.0) = 54.1 deg
Decl.(2000.0) = 6.1 deg
The 1 sigma statistical error radius is 3.2 deg.
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB261111477/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB261111477/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB261111477/json
GCN Circular 46224
Subject
GRB 261111A: Fermi GBM Final Real-time Localization
Date
2026-11-11T11:37:41Z (10 hours ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 11:27:07 UT on 11 Nov 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 261111A (trigger 816089232.948464 / 261111477).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 56.9, Dec = 5.8 (J2000 degrees, equivalent to J2000 03h 47m, 5d 47'), with a statistical uncertainty of 2.0 degrees.
The angle from the Fermi LAT boresight is 58.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261111477/quicklook/glg_skymap_all_bn261111477.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261111477/quicklook/glg_healpix_all_bn261111477.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn261111477/quicklook/glg_lc_medres34_bn261111477.gif