GCN Circular 44734

Subject
Fermi GRB 260529A: Global MASTER-Net observations report
Event
GRB 260529A
Date
2026-05-29T03:17:39Z (17 hours 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),
M. Segura,  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) started inspect of the Fermi GRB 260529A ( Fermi GBM team, GCN 44733Loading...
 
 ) errorbox  564 sec after notice time and 606 sec after trigger time at 2026-05-29 03:00:04 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 74 deg. The sun  altitude  is -66.9 deg. 

The galactic latitude b = -25 deg., longitude l = 28 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3345808

We obtain a following upper limits.  

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

     666 | 2026-05-29 03:00:04 |         MASTER-OAFA | (20h 10m 08.98s , -15d 23m 33.3s) |   C |   120 | 17.3 |        
     807 | 2026-05-29 03:02:10 |         MASTER-OAFA | (20h 10m 09.05s , -15d 23m 24.1s) |   C |   150 | 17.5 |        
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