GCN Circular 43550

Subject
EP260128a: Global MASTER-Net observations report
Event
EP260128a
Date
2026-01-29T06:54:20Z (4 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  [1]  located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP260128a ( EP Team et al., GCN 43549Loading...
 
 ) errorbox  9549 sec after notice time and 17258 sec after trigger time at 2026-01-29 04:27:37 UT, with upper limit up to  19.9 mag. The observations began at zenith distance = 21 deg. The sun  altitude  is -40.7 deg. 

The galactic latitude b = 18 deg., longitude l = 235 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3117956

We obtain a following upper limits.  

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

   17289 | 2026-01-29 04:27:37 |         MASTER-OAFA | (08h 29m 07.40s , -10d 15m 51.1s) |   C |    60 | 18.7 |        
   17364 | 2026-01-29 04:28:53 |         MASTER-OAFA | (08h 29m 12.43s , -10d 16m 52.4s) |   C |    60 | 13.8 |        
   25520 | 2026-01-29 06:44:48 |         MASTER-OAFA | (08h 33m 35.30s , -09d 55m 35.4s) |   C |    60 | 19.9 |        
   25597 | 2026-01-29 06:46:06 |         MASTER-OAFA | (08h 33m 42.32s , -09d 56m 34.0s) |   C |    60 | 19.9 |        
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