GCN Circular 42236

Subject
Fermi trigger No 782044789: Global MASTER-Net observations report
Date
2025-10-14T00:15:33Z (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-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB251013.44 (trigger No 782044789,16h 21m 00.00s , -23d 58m 58.8s, R=50) errorbox  46947 sec after notice time and 46980 sec after trigger time at 2025-10-13 23:42:44 UT, with upper limit up to  19.5 mag. Observations started at twilight.  The observations began at zenith distance =  6 deg. The sun  altitude  is -13.0 deg. 

The galactic latitude b = 18 deg., longitude l = 353 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3013722

We obtain a following upper limits.  

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

   47010 | 2025-10-13 23:42:44 |         MASTER-OAFA | (20h 11m 08.20s , -31d 38m 07.6s) |   C |    60 | 19.5 |        
   47086 | 2025-10-13 23:44:00 |         MASTER-OAFA | (20h 11m 08.28s , -31d 39m 50.4s) |   C |    60 | 19.3 |        
   47162 | 2025-10-13 23:45:15 |         MASTER-OAFA | (20h 11m 12.39s , -31d 38m 20.4s) |   C |    60 | 19.5 |        
Filter C is a clear (unfiltred) band. 


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