GCN Circular 42068

Subject

Swift GRB251003A: Global MASTER-Net observations report

Event

GRB 251003A

Date

2025-10-03T02:04:38Z (6 days ago)

Edited On

2025-10-05T16:40:05Z (4 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), A.Sosnovskij (CrAO RAS),
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  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB251003.08 (trigger No 1400964,01h 14m 00.72s , +56d 30m 25.2s, R=0.05) errorbox  10 sec after notice time and 34 sec after trigger time at 2025-10-03 01:59:04 UT, with upper limit up to  16.6 mag. Observations started at twilight.  The observations began at zenith distance = 43 deg. The sun  altitude  is -13.7 deg. 

The galactic latitude b = -6 deg., longitude l = 126 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3005736

We obtain a following upper limits.  

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

      40 |   MASTER-Kislovodsk |  P- |    10 | 15.8 |        
      50 |   MASTER-Kislovodsk |  P- |    30 | 16.4 |  Coadd 
      40 |   MASTER-Kislovodsk |  P| |    10 | 14.6 |        
      58 |   MASTER-Kislovodsk |  P- |    10 | 16.0 |        
      58 |   MASTER-Kislovodsk |  P| |    10 | 15.0 |        
      77 |   MASTER-Kislovodsk |  P- |    10 | 16.2 |        
      77 |   MASTER-Kislovodsk |  P| |    10 | 15.1 |        
     100 |   MASTER-Kislovodsk |  P- |    20 | 16.5 |        
     100 |   MASTER-Kislovodsk |  P| |    20 | 15.8 |        
     129 |   MASTER-Kislovodsk |  P- |    20 | 16.5 |        
     129 |   MASTER-Kislovodsk |  P| |    20 | 15.6 |        
     162 |   MASTER-Kislovodsk |  P- |    30 | 16.6 |        
     162 |   MASTER-Kislovodsk |  P| |    30 | 15.9 |        


The observation and reduction will continue. 
The message may be cited.