GCN Circular 43084

Subject
EP251212a: Global MASTER-Net observations report
Event
EP251212a
Date
2025-12-13T20:09:41Z (a day 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  [1]  located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP251212a ( EP Team et al., GCN 43081Loading...
 
 ) errorbox  7432 sec after notice time and 60333 sec after trigger time at 2025-12-13 06:29:42 UT, with upper limit up to  20.8 mag. The observations began at zenith distance = 21 deg. The sun  altitude  is -28.6 deg. 

MASTER-Tunka robotic telescope  located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the EP251212a errorbox  56042 sec after notice time and 1 days 22543 sec after trigger time at 2025-12-13 19:59:52 UT, with upper limit up to  17.4 mag. The observations began at zenith distance = 74 deg. The sun  altitude  is -45.8 deg. 

The galactic latitude b = 14 deg., longitude l = 249 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3069779

We obtain a following upper limits.  

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

   60363 | 2025-12-13 06:29:42 |         MASTER-OAFA | (08h 52m 06.66s , -23d 02m 09.3s) |   C |    60 | 20.0 |        
   60544 | 2025-12-13 06:32:43 |         MASTER-OAFA | (08h 52m 13.47s , -23d 02m 07.8s) |   C |    60 | 20.0 |        
   60724 | 2025-12-13 06:35:42 |         MASTER-OAFA | (08h 52m 12.36s , -23d 02m 47.2s) |   C |    60 | 19.8 |        
   60799 | 2025-12-13 06:36:58 |         MASTER-OAFA | (09h 00m 51.90s , -23d 01m 25.6s) |   C |    60 | 20.0 |        
   60949 | 2025-12-13 06:36:58 |         MASTER-OAFA | (09h 00m 51.89s , -23d 01m 25.7s) |   C |   360 | 20.8 |  Coadd 
   60878 | 2025-12-13 06:38:16 |         MASTER-OAFA | (09h 00m 52.01s , -23d 02m 51.7s) |   C |    60 | 20.0 |        
   60952 | 2025-12-13 06:39:31 |         MASTER-OAFA | (09h 00m 55.66s , -23d 01m 23.0s) |   C |    60 | 20.0 |        
   62872 | 2025-12-13 07:11:31 |         MASTER-OAFA | (09h 00m 51.73s , -23d 02m 08.7s) |   C |    60 | 20.0 |        
   62949 | 2025-12-13 07:12:47 |         MASTER-OAFA | (09h 00m 56.52s , -23d 01m 41.3s) |   C |    60 | 20.0 |        
   63023 | 2025-12-13 07:14:02 |         MASTER-OAFA | (09h 00m 54.42s , -23d 00m 05.6s) |   C |    60 | 20.1 |        
  108959 | 2025-12-13 19:59:52 |        MASTER-Tunka | (08h 56m 23.31s , -22d 50m 56.5s) |   C |    30 | 15.9 |        
  109002 | 2025-12-13 20:00:36 |        MASTER-Tunka | (08h 56m 22.49s , -22d 49m 57.8s) |   C |    30 | 15.9 |        
  109050 | 2025-12-13 20:01:24 |        MASTER-Tunka | (08h 56m 28.21s , -22d 50m 58.5s) |   C |    30 | 16.2 |        
  109094 | 2025-12-13 20:02:07 |        MASTER-Tunka | (08h 56m 21.99s , -22d 52m 00.7s) |   C |    30 | 16.6 |        
  109094 | 2025-12-13 20:02:07 |        MASTER-Tunka | (08h 56m 04.58s , -22d 45m 54.5s) |   C |    30 | 14.9 |        
  109145 | 2025-12-13 20:02:58 |        MASTER-Tunka | (08h 56m 27.67s , -22d 51m 54.9s) |   C |    30 | 16.9 |        
  109145 | 2025-12-13 20:02:58 |        MASTER-Tunka | (08h 56m 11.31s , -22d 45m 17.0s) |   C |    30 | 12.4 |        
  109186 | 2025-12-13 20:03:40 |        MASTER-Tunka | (08h 56m 25.45s , -22d 50m 22.2s) |   C |    30 | 17.3 |        
  109186 | 2025-12-13 20:03:40 |        MASTER-Tunka | (08h 56m 06.73s , -22d 43m 38.7s) |   C |    30 | 13.0 |        
  109230 | 2025-12-13 20:04:23 |        MASTER-Tunka | (08h 56m 25.51s , -22d 52m 02.9s) |   C |    30 | 17.4 |        
  109230 | 2025-12-13 20:04:23 |        MASTER-Tunka | (08h 56m 06.86s , -22d 45m 19.2s) |   C |    30 | 12.9 |        
  109273 | 2025-12-13 20:05:06 |        MASTER-Tunka | (08h 56m 13.03s , -22d 43m 50.4s) |   C |    30 | 12.6 |        
Filter C is a clear (unfiltred) band. 


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

[1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023,  Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp.
http : // www.pereplet.ru/lipunov/625.html