GCN Circular 42788

Subject
Fermi trigger No 785388351: Global MASTER-Net observations report
Date
2025-11-21T14:45:55Z (3 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
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, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile,  F. Podesta, R.Podesta, E. Gonzalez  (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 

MASTER-Kislovodsk robotic telescope  [1]  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB251121.14 (trigger No 785388351,21h 39m 12.00s , +42d 06m 36.0s, R=11.36) errorbox  39901 sec after notice time and 39938 sec after trigger time at 2025-11-21 14:31:24 UT, with upper limit up to  16.5 mag. Observations started at twilight.  The observations began at zenith distance =  2 deg. The sun  altitude  is -9.1 deg. 

The galactic latitude b = -8 deg., longitude l = 90 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3048278

We obtain a following upper limits.  

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

   39968 | 2025-11-21 14:31:24 |   MASTER-Kislovodsk | (21h 28m 33.86s , +41d 27m 00.7s) |   C |    60 | 15.6 |        
   39968 | 2025-11-21 14:31:24 |   MASTER-Kislovodsk | (21h 34m 49.78s , +41d 04m 07.6s) |   C |    60 | 14.0 |        
   40048 | 2025-11-21 14:32:44 |   MASTER-Kislovodsk | (21h 47m 06.83s , +43d 20m 11.1s) |   C |    60 | 16.0 |        
   40048 | 2025-11-21 14:32:44 |   MASTER-Kislovodsk | (21h 53m 30.83s , +42d 57m 01.9s) |   C |    60 | 13.4 |        
   40227 | 2025-11-21 14:35:43 |   MASTER-Kislovodsk | (21h 49m 03.50s , +41d 25m 22.5s) |   C |    60 | 16.1 |        
   40227 | 2025-11-21 14:35:44 |   MASTER-Kislovodsk | (21h 55m 10.89s , +41d 02m 46.0s) |   C |    60 | 14.1 |        
   40308 | 2025-11-21 14:37:04 |   MASTER-Kislovodsk | (21h 32m 22.61s , +39d 32m 55.4s) |   C |    60 | 16.1 |        
   40308 | 2025-11-21 14:37:04 |   MASTER-Kislovodsk | (21h 38m 18.31s , +39d 09m 16.6s) |   C |    60 | 13.7 |        
   40388 | 2025-11-21 14:38:24 |   MASTER-Kislovodsk | (21h 52m 03.41s , +39d 31m 14.7s) |   C |    60 | 16.5 |        
   40388 | 2025-11-21 14:38:24 |   MASTER-Kislovodsk | (21h 58m 00.63s , +39d 07m 52.4s) |   C |    60 | 14.0 |        
   40474 | 2025-11-21 14:39:50 |   MASTER-Kislovodsk | (21h 30m 34.79s , +41d 17m 12.7s) |   C |    60 | 16.2 |        
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