GCN Circular 42962

Subject
Fermi GRB 251202B: Global MASTER-Net observations report
Event
GRB 251202B
Date
2025-12-02T19:00:24Z (9 hours 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-SAAO robotic telescope  [1]  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 251202B ( Fermi GBM team, GCN 42961Loading...
 
 ) errorbox  566 sec after notice time and 598 sec after trigger time at 2025-12-02 18:37:01 UT, with upper limit up to  19.2 mag. Observations started at twilight.  The observations began at zenith distance = 24 deg. The sun  altitude  is -12.7 deg. 

The galactic latitude b = -67 deg., longitude l = 38 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3058648

We obtain a following upper limits.  

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

     629 | 2025-12-02 18:37:01 |         MASTER-SAAO | (23h 04m 42.90s , -23d 23m 21.3s) |   C |    60 | 17.6 |        
     629 | 2025-12-02 18:37:01 |         MASTER-SAAO | (23h 06m 42.31s , -23d 38m 56.2s) |   C |    60 | 18.4 |        
     689 | 2025-12-02 18:37:01 |         MASTER-SAAO | (23h 06m 42.31s , -23d 38m 56.2s) |   C |   180 | 19.2 |  Coadd 
     708 | 2025-12-02 18:38:20 |         MASTER-SAAO | (23h 04m 42.92s , -23d 23m 16.2s) |   C |    60 | 17.6 |        
     708 | 2025-12-02 18:38:20 |         MASTER-SAAO | (23h 06m 42.32s , -23d 38m 51.7s) |   C |    60 | 18.4 |        
     787 | 2025-12-02 18:39:39 |         MASTER-SAAO | (23h 04m 42.96s , -23d 23m 12.1s) |   C |    60 | 17.7 |        
     787 | 2025-12-02 18:39:40 |         MASTER-SAAO | (23h 06m 42.35s , -23d 38m 48.1s) |   C |    60 | 18.4 |        
     866 | 2025-12-02 18:40:58 |         MASTER-SAAO | (23h 04m 43.00s , -23d 23m 08.4s) |   C |    60 | 17.7 |        
     866 | 2025-12-02 18:40:58 |         MASTER-SAAO | (23h 06m 42.37s , -23d 38m 45.0s) |   C |    60 | 18.5 |        
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