GCN Circular 46152

Subject
SVOM GRB261104.86: Global MASTER-Net observations report
Event
GRB 261104.86
Date
2026-11-04T22:28:32Z (8 hours ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
D.Buckley (SAAO),

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 (Lomonosov MSU)

A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
A.Sosnovskij (Lomonosov MSU)

A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory)

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)

R.Rebolo (The Instituto de Astrofisica de Canarias)

O.Gress, N.Budnev(ISU)

M. Segura,  F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA)


MASTER-SAAO robotic telescope  [1]  located in South Africa (South African Astronomical Observatory) was pointed to the SVOM GRB261104.86 (trigger No 1793824591,00h 25m 11.98s , -54d 27m 40.3s, R=0.1635) errorbox  1547 sec after notice time and 2228 sec after trigger time at 2026-11-04 21:13:39 UT, with upper limit up to  19.7 mag. The observations began at zenith distance = 26 deg. The sun  altitude  is -39.7 deg. 

The galactic latitude b = -63 deg., longitude l = 311 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3532317

We obtain a following upper limits.  

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

    2258 | 2026-11-04 21:13:39 |         MASTER-SAAO | (00h 22m 49.96s , -54d 45m 31.1s) |   C |    60 | 19.7 |        
    2258 | 2026-11-04 21:13:39 |         MASTER-SAAO | (00h 19m 44.57s , -54d 29m 56.6s) |   C |    60 | 19.5 |        
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