GCN Circular 44149

Subject
Fermi trigger No 796485221: Global MASTER-Net observations report
Date
2026-03-29T23:31:14Z (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-SAAO robotic telescope  [1]  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB260329.58 (trigger No 796485221,19h 47m 48.00s , -55d 55m 12.0s, R=7.59) errorbox  33703 sec after notice time and 33736 sec after trigger time at 2026-03-29 23:15:52 UT, with upper limit up to  18.9 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -60.5 deg. 

The galactic latitude b = -30 deg., longitude l = 342 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3219478

We obtain a following upper limits.  

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

   33796 | 2026-03-29 23:15:52 |         MASTER-SAAO | (19h 42m 30.66s , -55d 55m 47.3s) |   C |   120 | 18.7 |        
   33796 | 2026-03-29 23:15:52 |         MASTER-SAAO | (19h 45m 45.76s , -56d 11m 20.9s) |   C |   120 | 18.7 |        
   33948 | 2026-03-29 23:18:24 |         MASTER-SAAO | (19h 42m 36.60s , -55d 56m 48.4s) |   C |   120 | 18.8 |        
   33948 | 2026-03-29 23:18:24 |         MASTER-SAAO | (19h 45m 51.90s , -56d 12m 19.9s) |   C |   120 | 18.8 |        
   34100 | 2026-03-29 23:20:56 |         MASTER-SAAO | (19h 17m 26.52s , -55d 57m 25.2s) |   C |   120 | 18.6 |        
   34100 | 2026-03-29 23:20:56 |         MASTER-SAAO | (19h 20m 42.35s , -56d 12m 54.8s) |   C |   120 | 18.9 |        
   34252 | 2026-03-29 23:23:28 |         MASTER-SAAO | (19h 17m 32.63s , -55d 57m 06.4s) |   C |   120 | 18.6 |        
   34252 | 2026-03-29 23:23:28 |         MASTER-SAAO | (19h 20m 48.48s , -56d 12m 34.7s) |   C |   120 | 18.8 |        
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