GCN Circular 45521

Subject
EP Alert 260905.11: Global MASTER-Net observations report
Date
2026-09-05T07:09:34Z (2 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 (CrAO RAS)

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 EP Alert 260905.11 (trigger No 1709302592,01h 56m 53.76s , +30d 32m 52.8s, R=0.0511404) errorbox  14952 sec after notice time and 15834 sec after trigger time at 2026-09-05 06:57:23 UT, with upper limit up to  20.2 mag. The observations began at zenith distance = 63 deg. The sun  altitude  is -48.5 deg. 

The galactic latitude b = -30 deg., longitude l = 140 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3499126

We obtain a following upper limits.  

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

   15864 | 2026-09-05 06:57:23 |         MASTER-OAFA | (01h 55m 24.84s , +30d 20m 10.1s) |   C |    60 | 19.6 |        
   15924 | 2026-09-05 06:57:23 |         MASTER-OAFA | (01h 55m 24.84s , +30d 20m 10.1s) |   C |   180 | 20.2 |  Coadd 
   15944 | 2026-09-05 06:58:43 |         MASTER-OAFA | (01h 55m 21.04s , +30d 21m 46.1s) |   C |    60 | 19.6 |        
   16025 | 2026-09-05 07:00:04 |         MASTER-OAFA | (01h 55m 20.15s , +30d 20m 05.9s) |   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