GCN Circular 43004

Subject

Swift GRB251205A: Global MASTER-Net observations report

Event

GRB 251205A

Date

2025-12-05T23:48:53Z (2 days ago)

Edited On

2025-12-06T01:53:46Z (2 days ago)

From

Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

Edited By

Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Vladimir Lipunov at Lomonosov Moscow State University <lipunov@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) was pointed to the Swift GRB251205.99 (trigger No 1420873,13h 20m 58.42s , +29d 57m 45.0s, R=0.05) errorbox  19 sec after notice time and 92 sec after trigger time at 2025-12-05 23:41:19 UT, with upper limit up to  17.0 mag. The observations began at zenith distance = 68 deg. The sun  altitude  is -51.1 deg. 

The galactic latitude b = 83 deg., longitude l = 55 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3062088

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     103 |   MASTER-Kislovodsk |  P- |    20 | 16.6 |        
     103 |   MASTER-Kislovodsk |  P| |    20 | 16.5 |        
     131 |   MASTER-Kislovodsk |  P- |    20 | 16.3 |        
     131 |   MASTER-Kislovodsk |  P| |    20 | 16.5 |        
     164 |   MASTER-Kislovodsk |  P- |    30 | 16.8 |        
     164 |   MASTER-Kislovodsk |  P| |    30 | 16.8 |        
     208 |   MASTER-Kislovodsk |  P- |    40 | 16.8 |        
     208 |   MASTER-Kislovodsk |  P| |    40 | 16.8 |        
     261 |   MASTER-Kislovodsk |  P- |    50 | 17.0 |        
     261 |   MASTER-Kislovodsk |  P| |    50 | 17.0 |        


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