GCN Circular 42059

Subject

Fermi GRB 251002A: Global MASTER-Net observations report

Date

2025-10-02T20:30:48Z (6 days ago)

Edited On

2025-10-03T19:08:58Z (5 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  (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) started inspect of the Fermi GRB251002.84 (trigger No 781128896,01h 12m 38.40s , -05d 24m 00.0s, R=5.51) errorbox  259 sec after notice time and 291 sec after trigger time at 2025-10-02 20:19:42 UT, with upper limit up to  18.4 mag. The observations began at zenith distance = 50 deg. The sun  altitude  is -49.8 deg. 

The galactic latitude b = -67 deg., longitude l = 138 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3005496

We obtain a following upper limits.  

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

     322 | 2025-10-02 20:19:42 |   MASTER-Kislovodsk | (00h 53m 34.79s , -05d 12m 04.9s) |  P- |    60 | 17.4 |        
     402 | 2025-10-02 20:19:42 |   MASTER-Kislovodsk | (00h 53m 34.79s , -05d 12m 04.8s) |  P- |   220 | 18.4 |  Coadd 
     322 | 2025-10-02 20:19:42 |   MASTER-Kislovodsk | (00h 53m 50.27s , -05d 35m 28.4s) |  P| |    60 | 18.0 |        
     395 | 2025-10-02 20:20:50 |   MASTER-Kislovodsk | (00h 53m 34.79s , -05d 12m 08.8s) |  P- |    70 | 18.1 |        
     395 | 2025-10-02 20:20:50 |   MASTER-Kislovodsk | (00h 53m 50.31s , -05d 35m 30.7s) |  P| |    70 | 18.0 |        
     483 | 2025-10-02 20:22:09 |   MASTER-Kislovodsk | (00h 53m 34.83s , -05d 12m 10.6s) |  P- |    90 | 18.1 |        
     483 | 2025-10-02 20:22:09 |   MASTER-Kislovodsk | (00h 53m 50.43s , -05d 35m 32.0s) |  P| |    90 | 18.1 |        
     592 | 2025-10-02 20:23:47 |   MASTER-Kislovodsk | (00h 53m 34.96s , -05d 12m 12.3s) |  P- |   110 | 18.4 |        
     592 | 2025-10-02 20:23:47 |   MASTER-Kislovodsk | (00h 53m 50.58s , -05d 35m 34.4s) |  P| |   110 | 18.1 |        


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