GCN Circular 43786

Subject
Fermi GRB 260219A: Global MASTER-Net observations report
Event
GRB 260219A
Date
2026-02-19T18:36:32Z (5 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-Tunka robotic telescope  [1]  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 260219A ( Fermi GBM team, GCN 43785Loading...
 
 ) errorbox  8595 sec after notice time and 8760 sec after trigger time at 2026-02-19 16:30:53 UT, with upper limit up to  19.8 mag. The observations began at zenith distance = 44 deg. The sun  altitude  is -49.0 deg. 

The galactic latitude b = 61 deg., longitude l = 245 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3145377

We obtain a following upper limits.  

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

    8790 | 2026-02-19 16:30:53 |        MASTER-Tunka | (11h 07m 54.97s , +13d 08m 20.3s) |   C |    60 | 19.0 |        
    8790 | 2026-02-19 16:30:53 |        MASTER-Tunka | (11h 07m 34.84s , +13d 15m 31.6s) |   C |    60 | 19.0 |        
    9759 | 2026-02-19 16:47:02 |        MASTER-Tunka | (11h 03m 29.25s , +11d 14m 56.3s) |   C |    60 | 19.4 |        
    9759 | 2026-02-19 16:47:02 |        MASTER-Tunka | (11h 03m 09.30s , +11d 21m 54.5s) |   C |    60 | 19.3 |        
   10877 | 2026-02-19 17:05:40 |        MASTER-Tunka | (11h 18m 34.85s , +11d 21m 16.4s) |   C |    60 | 19.7 |        
   10877 | 2026-02-19 17:05:40 |        MASTER-Tunka | (11h 18m 55.04s , +11d 14m 26.8s) |   C |    60 | 19.8 |        
   12397 | 2026-02-19 17:31:00 |        MASTER-Tunka | (11h 15m 03.51s , +09d 19m 24.2s) |   C |    60 | 17.4 |        
   12397 | 2026-02-19 17:31:00 |        MASTER-Tunka | (11h 14m 42.55s , +09d 26m 02.0s) |   C |    60 | 17.4 |        
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