GCN 43494: Fermi GRB 260120C: Global MASTER-Net observations report

2026-01-22T00:30:53.397Z | rev 0 | event: GRB 260120C
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-Kislovodsk robotic telescope  [1]  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 260120C ( Fermi GBM team, GCN 43482) errorbox  1 days 3994 sec after notice time and 1 days 4027 sec after trigger time at 2026-01-22 00:14:13 UT, with upper limit up to  16.8 mag. The observations began at zenith distance = 81 deg. The sun  altitude  is -47.2 deg. 

The galactic latitude b = 20 deg., longitude l = 26 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3110218

We obtain a following upper limits.  

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

   44777 | 2026-01-21 11:32:53 |             MASTER- | (17h 17m 02.82s , +06d 50m 25.2s) |   C |    60 | 18.4 |        
   44777 | 2026-01-21 11:32:53 |             MASTER- | (17h 18m 05.82s , +06d 16m 01.2s) |   C |    60 | 18.4 |        
   44847 | 2026-01-21 11:34:03 |             MASTER- | (17h 25m 13.44s , +06d 50m 33.0s) |   C |    60 | 18.3 |        
   44847 | 2026-01-21 11:34:03 |             MASTER- | (17h 26m 16.06s , +06d 16m 06.1s) |   C |    60 | 18.2 |        
   45387 | 2026-01-21 11:43:03 |             MASTER- | (17h 18m 07.00s , +06d 16m 05.5s) |   C |    60 | 18.6 |        
   45387 | 2026-01-21 11:43:03 |             MASTER- | (17h 17m 03.38s , +06d 50m 02.6s) |   C |    60 | 18.5 |        
   45457 | 2026-01-21 11:44:13 |             MASTER- | (17h 26m 15.40s , +06d 16m 14.1s) |   C |    60 | 18.5 |        
   45457 | 2026-01-21 11:44:13 |             MASTER- | (17h 25m 12.21s , +06d 50m 13.9s) |   C |    60 | 18.4 |        
   46057 | 2026-01-21 11:54:13 |             MASTER- | (17h 17m 05.56s , +06d 51m 19.0s) |   C |    60 | 18.6 |        
   46057 | 2026-01-21 11:54:13 |             MASTER- | (17h 18m 09.53s , +06d 17m 03.8s) |   C |    60 | 18.8 |        
   46127 | 2026-01-21 11:55:23 |             MASTER- | (17h 25m 09.25s , +06d 49m 58.4s) |   C |    60 | 18.5 |        
   46127 | 2026-01-21 11:55:23 |             MASTER- | (17h 26m 12.91s , +06d 15m 41.0s) |   C |    60 | 18.6 |        
   46661 | 2026-01-21 12:04:17 |             MASTER- | (17h 18m 10.15s , +06d 16m 41.1s) |   C |    60 | 19.0 |        
   46661 | 2026-01-21 12:04:17 |             MASTER- | (17h 17m 05.20s , +06d 51m 05.2s) |   C |    60 | 18.7 |        
   46730 | 2026-01-21 12:05:26 |             MASTER- | (17h 25m 08.92s , +06d 49m 31.9s) |   C |    60 | 18.5 |        
   46730 | 2026-01-21 12:05:26 |             MASTER- | (17h 26m 13.45s , +06d 15m 06.0s) |   C |    60 | 18.8 |        
   47327 | 2026-01-21 12:15:23 |             MASTER- | (17h 17m 06.31s , +06d 49m 15.8s) |   C |    60 | 18.7 |        
   47327 | 2026-01-21 12:15:23 |             MASTER- | (17h 18m 11.40s , +06d 14m 44.7s) |   C |    60 | 19.0 |        
   47398 | 2026-01-21 12:16:33 |             MASTER- | (17h 25m 11.28s , +06d 50m 36.4s) |   C |    60 | 18.6 |        
   47398 | 2026-01-21 12:16:34 |             MASTER- | (17h 26m 16.13s , +06d 16m 02.5s) |   C |    60 | 18.9 |        
   47994 | 2026-01-21 12:26:30 |             MASTER- | (17h 17m 04.57s , +06d 49m 46.2s) |   C |    60 | 18.7 |        
   47994 | 2026-01-21 12:26:30 |             MASTER- | (17h 18m 10.96s , +06d 15m 15.9s) |   C |    60 | 19.1 |        
   48064 | 2026-01-21 12:27:40 |             MASTER- | (17h 25m 06.47s , +06d 50m 37.4s) |   C |    60 | 18.7 |        
   48064 | 2026-01-21 12:27:40 |             MASTER- | (17h 26m 12.55s , +06d 16m 04.5s) |   C |    60 | 19.1 |        
   90457 | 2026-01-22 00:14:13 |   MASTER-Kislovodsk | (16h 55m 40.00s , +10d 25m 13.1s) |   C |    60 | 16.7 |        
   90573 | 2026-01-22 00:16:09 |   MASTER-Kislovodsk | (17h 02m 50.35s , +12d 18m 51.1s) |   C |    60 | 16.7 |        
   90811 | 2026-01-22 00:20:07 |   MASTER-Kislovodsk | (16h 45m 12.41s , +06d 36m 17.1s) |   C |    60 | 16.8 |        
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