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GCN Circular 40904

Subject

Fermi GRB 250702B: Global MASTER-Net observations report

Event

GRB 250702B

Date

2025-07-03T02:15:23Z (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-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 250702B ( Fermi GBM team, GCN 40883Loading...
 
 ) errorbox  36852 sec after notice time and 36888 sec after trigger time at 2025-07-03 00:10:54 UT, with upper limit up to  18.6 mag. The observations began at zenith distance = 28 deg. The sun  altitude  is -68.5 deg. 

The galactic latitude b = -7 deg., longitude l = 27 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2923151

We obtain a following upper limits.  

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

   36919 | 2025-07-03 00:10:54 |         MASTER-SAAO | (18h 58m 11.78s , -10d 24m 39.1s) |   C |    60 | 18.2 |        
   37016 | 2025-07-03 00:12:31 |         MASTER-SAAO | (19h 06m 18.96s , -10d 26m 55.8s) |   C |    60 | 18.6 |        
Filter C is a clear (unfiltred) band. 


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