GCN Circular 45609

Subject
SVOM GRB260917.16: Global MASTER-Net observations report
Event
GRB 260917.16
Date
2026-09-17T08:57:44Z (3 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
M. Segura,  F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA)

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)

D.Buckley (SAAO),

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)


MASTER-OAFA robotic telescope  [1]  located in Argentina (OAFA observatory of San Juan National University) was pointed to the SVOM GRB260917.16 (trigger No 1789617132,03h 07m 27.50s , +25d 29m 01.0s, R=0.1473) errorbox  17228 sec after notice time and 17842 sec after trigger time at 2026-09-17 08:49:34 UT, with upper limit up to  20.0 mag. The observations began at zenith distance = 59 deg. The sun  altitude  is -22.6 deg. 

The galactic latitude b = -27 deg., longitude l = 158 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3505665

We obtain a following upper limits.  

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

   17873 | 2026-09-17 08:49:34 |         MASTER-OAFA | (03h 06m 37.81s , +25d 26m 58.0s) |   C |    60 | 20.0 |        
   17949 | 2026-09-17 08:50:50 |         MASTER-OAFA | (03h 06m 31.93s , +25d 26m 11.5s) |   C |    60 | 19.9 |        
   18028 | 2026-09-17 08:52:09 |         MASTER-OAFA | (03h 06m 32.79s , +25d 27m 14.5s) |   C |    60 | 20.0 |        
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