GCN Circular 43152

Subject
SVOM GRB251219.11: Global MASTER-Net observations report
Event
GRB 251219.11
Date
2025-12-19T02:56:55Z (2 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-OAFA robotic telescope  [1]  located in Argentina (OAFA observatory of San Juan National University) started inspect of the SVOM GRB251219.11 (trigger No 1766111792,04h 46m 20.50s , -33d 01m 10.2s, R=1) errorbox  29 sec after notice time and 58 sec after trigger time at 2025-12-19 02:37:29 UT, with upper limit up to  20.2 mag. The observations began at zenith distance = 12 deg. The sun  altitude  is -29.1 deg. 

The galactic latitude b = -39 deg., longitude l = 235 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3076431

We obtain a following upper limits.  

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

      63 | 2025-12-19 02:37:29 |         MASTER-OAFA | (04h 46m 42.87s , -33d 06m 20.3s) |   C |    10 | 19.2 |        
      81 | 2025-12-19 02:37:47 |         MASTER-OAFA | (04h 46m 42.91s , -33d 06m 20.5s) |   C |    10 | 19.2 |        
     104 | 2025-12-19 02:38:05 |         MASTER-OAFA | (04h 46m 42.96s , -33d 06m 20.4s) |   C |    20 | 19.7 |        
     131 | 2025-12-19 02:38:32 |         MASTER-OAFA | (04h 46m 43.03s , -33d 06m 20.2s) |   C |    20 | 19.8 |        
     184 | 2025-12-19 02:39:20 |         MASTER-OAFA | (04h 46m 43.11s , -33d 06m 19.5s) |   C |    30 | 18.4 |        
     227 | 2025-12-19 02:39:58 |         MASTER-OAFA | (04h 46m 43.21s , -33d 06m 19.3s) |   C |    40 | 20.1 |        
     278 | 2025-12-19 02:40:44 |         MASTER-OAFA | (04h 46m 43.31s , -33d 06m 18.8s) |   C |    50 | 20.2 |        
     340 | 2025-12-19 02:41:41 |         MASTER-OAFA | (04h 46m 43.43s , -33d 06m 18.1s) |   C |    60 | 20.2 |        
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