GCN Circular 46229

Subject
Fermi GRB 261111A: Global MASTER-Net observations report
Event
GRB 261111A
Date
2026-11-11T19:01:00Z (3 hours ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
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 46224Loading...
 
 ) 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