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GCN Circular 40930

Subject
Fermi GRB 250703A: Global MASTER-Net observations report
Event
GRB 250703A
Date
2025-07-04T03:30:23Z (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-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250703A ( Fermi GBM team, GCN 40909Loading...
 
 ) errorbox  54105 sec after notice time and 54115 sec after trigger time at 2025-07-04 00:09:27 UT, with upper limit up to  19.1 mag. The observations began at zenith distance = 65 deg. The sun  altitude  is -68.8 deg. 

The galactic latitude b = -27 deg., longitude l = 88 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2924032

We obtain a following upper limits.  

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

   54146 | 2025-07-04 00:09:27 |         MASTER-SAAO | (22h 26m 03.93s , +25d 31m 00.0s) |   C |    60 | 18.5 |        
   54146 | 2025-07-04 00:09:27 |         MASTER-SAAO | (22h 24m 08.95s , +25d 46m 54.4s) |   C |    60 | 18.4 |        
   54360 | 2025-07-04 00:13:01 |         MASTER-SAAO | (22h 34m 58.48s , +25d 30m 12.9s) |   C |    60 | 19.1 |        
   54360 | 2025-07-04 00:13:01 |         MASTER-SAAO | (22h 33m 03.49s , +25d 46m 08.2s) |   C |    60 | 19.0 |        
   54650 | 2025-07-04 00:17:51 |         MASTER-SAAO | (22h 22m 02.32s , +23d 35m 41.4s) |   C |    60 | 19.0 |        
   54744 | 2025-07-04 00:19:25 |         MASTER-SAAO | (22h 30m 48.83s , +23d 37m 23.1s) |   C |    60 | 18.4 |        
   54744 | 2025-07-04 00:19:25 |         MASTER-SAAO | (22h 28m 54.92s , +23d 53m 18.7s) |   C |    60 | 18.4 |        
   54838 | 2025-07-04 00:20:59 |         MASTER-SAAO | (22h 26m 00.65s , +25d 30m 36.9s) |   C |    60 | 17.6 |        
   54838 | 2025-07-04 00:20:59 |         MASTER-SAAO | (22h 24m 05.05s , +25d 46m 32.8s) |   C |    60 | 17.5 |        
   55038 | 2025-07-04 00:24:19 |         MASTER-SAAO | (22h 34m 59.98s , +25d 30m 21.6s) |   C |    60 | 18.7 |        
   55038 | 2025-07-04 00:24:19 |         MASTER-SAAO | (22h 33m 04.25s , +25d 46m 18.0s) |   C |    60 | 18.6 |        
   55530 | 2025-07-04 00:32:31 |         MASTER-SAAO | (22h 22m 03.38s , +23d 35m 59.0s) |   C |    60 | 16.4 |        
   55624 | 2025-07-04 00:34:05 |         MASTER-SAAO | (22h 30m 50.57s , +23d 37m 31.6s) |   C |    60 | 18.2 |        
   55624 | 2025-07-04 00:34:05 |         MASTER-SAAO | (22h 28m 55.96s , +23d 53m 28.4s) |   C |    60 | 18.1 |        
   55717 | 2025-07-04 00:35:38 |         MASTER-SAAO | (22h 26m 03.12s , +25d 30m 45.9s) |   C |    60 | 16.1 |        
   55717 | 2025-07-04 00:35:38 |         MASTER-SAAO | (22h 24m 06.74s , +25d 46m 43.2s) |   C |    60 | 16.1 |        
   58382 | 2025-07-04 01:20:03 |         MASTER-SAAO | (22h 34m 57.08s , +25d 32m 08.2s) |   C |    60 | 17.9 |        
   58382 | 2025-07-04 01:20:03 |         MASTER-SAAO | (22h 33m 00.18s , +25d 47m 59.5s) |   C |    60 | 17.7 |        
   59961 | 2025-07-04 01:46:22 |         MASTER-SAAO | (22h 22m 20.57s , +23d 37m 14.0s) |   C |    60 | 18.6 |        
   59961 | 2025-07-04 01:46:22 |         MASTER-SAAO | (22h 20m 26.03s , +23d 53m 02.5s) |   C |    60 | 18.4 |        
   60055 | 2025-07-04 01:47:56 |         MASTER-SAAO | (22h 31m 09.34s , +23d 37m 00.4s) |   C |    60 | 17.5 |        
   60055 | 2025-07-04 01:47:56 |         MASTER-SAAO | (22h 29m 14.85s , +23d 52m 49.9s) |   C |    60 | 17.3 |        
   60151 | 2025-07-04 01:49:32 |         MASTER-SAAO | (22h 26m 26.43s , +25d 32m 54.5s) |   C |    60 | 16.6 |        
   60151 | 2025-07-04 01:49:32 |         MASTER-SAAO | (22h 24m 30.30s , +25d 48m 45.4s) |   C |    60 | 16.3 |        
   60345 | 2025-07-04 01:52:46 |         MASTER-SAAO | (22h 35m 20.05s , +25d 32m 35.8s) |   C |    60 | 15.5 |        
   60345 | 2025-07-04 01:52:46 |         MASTER-SAAO | (22h 33m 23.77s , +25d 48m 27.9s) |   C |    60 | 15.3 |        
Filter C is a clear (unfiltred) band. 


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