GCN Circular 45763
Subject
Fermi GRB 260926A: Global MASTER-Net observations report
Event
Date
2026-09-26T17:31:32Z (5 hours ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
O.Gress, N.Budnev(ISU)
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)
M. Segura, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA)
MASTER-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 260926A ( Fermi GBM team, GCN 45761) errorbox 94 sec after notice time and 126 sec after trigger time at 2026-09-26 16:22:21 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 23 deg. The sun altitude is -38.9 deg.
The galactic latitude b = 3 deg., longitude l = 126 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3512177
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
137 | 2026-09-26 16:22:21 | MASTER-Tunka | (01h 52m 49.46s , +67d 56m 33.0s) | C | 20 | 18.0 |
157 | 2026-09-26 16:22:21 | MASTER-Tunka | (01h 52m 49.45s , +67d 56m 33.0s) | C | 60 | 18.5 | Coadd
137 | 2026-09-26 16:22:21 | MASTER-Tunka | (01h 54m 13.21s , +67d 47m 48.4s) | C | 20 | 18.1 |
160 | 2026-09-26 16:22:44 | MASTER-Tunka | (01h 52m 49.35s , +67d 56m 32.1s) | C | 20 | 17.9 |
160 | 2026-09-26 16:22:44 | MASTER-Tunka | (01h 54m 13.11s , +67d 47m 47.7s) | C | 20 | 18.1 |
184 | 2026-09-26 16:23:08 | MASTER-Tunka | (01h 52m 49.24s , +67d 56m 31.4s) | C | 20 | 17.8 |
184 | 2026-09-26 16:23:08 | MASTER-Tunka | (01h 54m 12.99s , +67d 47m 47.0s) | C | 20 | 17.9 |
205 | 2026-09-26 16:23:32 | MASTER-Tunka | (01h 52m 49.12s , +67d 56m 30.8s) | C | 15 | 17.6 |
220 | 2026-09-26 16:23:32 | MASTER-Tunka | (01h 52m 49.11s , +67d 56m 30.8s) | C | 45 | 18.2 | Coadd
205 | 2026-09-26 16:23:32 | MASTER-Tunka | (01h 54m 12.91s , +67d 47m 46.5s) | C | 15 | 17.7 |
220 | 2026-09-26 16:23:32 | MASTER-Tunka | (01h 54m 12.91s , +67d 47m 46.4s) | C | 45 | 18.2 | Coadd
224 | 2026-09-26 16:23:50 | MASTER-Tunka | (01h 52m 49.04s , +67d 56m 30.2s) | C | 15 | 17.5 |
224 | 2026-09-26 16:23:50 | MASTER-Tunka | (01h 54m 12.82s , +67d 47m 46.1s) | C | 15 | 17.7 |
242 | 2026-09-26 16:24:09 | MASTER-Tunka | (01h 52m 48.94s , +67d 56m 29.5s) | C | 15 | 17.6 |
243 | 2026-09-26 16:24:09 | MASTER-Tunka | (01h 54m 12.75s , +67d 47m 45.5s) | C | 15 | 17.6 |
261 | 2026-09-26 16:24:27 | MASTER-Tunka | (01h 52m 48.85s , +67d 56m 29.0s) | C | 15 | 17.6 |
276 | 2026-09-26 16:24:27 | MASTER-Tunka | (01h 52m 48.84s , +67d 56m 29.0s) | C | 45 | 18.2 | Coadd
261 | 2026-09-26 16:24:27 | MASTER-Tunka | (01h 54m 12.68s , +67d 47m 45.2s) | C | 15 | 17.6 |
276 | 2026-09-26 16:24:27 | MASTER-Tunka | (01h 54m 12.68s , +67d 47m 45.1s) | C | 45 | 18.3 | Coadd
279 | 2026-09-26 16:24:46 | MASTER-Tunka | (01h 52m 48.75s , +67d 56m 28.5s) | C | 15 | 17.6 |
280 | 2026-09-26 16:24:46 | MASTER-Tunka | (01h 54m 12.60s , +67d 47m 44.8s) | C | 15 | 17.7 |
298 | 2026-09-26 16:25:04 | MASTER-Tunka | (01h 52m 48.66s , +67d 56m 27.9s) | C | 15 | 17.6 |
298 | 2026-09-26 16:25:04 | MASTER-Tunka | (01h 54m 12.54s , +67d 47m 44.3s) | C | 15 | 17.8 |
316 | 2026-09-26 16:25:23 | MASTER-Tunka | (01h 52m 48.58s , +67d 56m 27.3s) | C | 15 | 17.7 |
317 | 2026-09-26 16:25:23 | MASTER-Tunka | (01h 54m 12.49s , +67d 47m 43.9s) | C | 15 | 17.8 |
594 | 2026-09-26 16:30:01 | MASTER-Tunka | (01h 17m 01.24s , +65d 03m 25.5s) | C | 15 | 17.4 |
609 | 2026-09-26 16:30:01 | MASTER-Tunka | (01h 17m 01.23s , +65d 03m 25.5s) | C | 45 | 17.9 | Coadd
594 | 2026-09-26 16:30:01 | MASTER-Tunka | (01h 18m 17.43s , +64d 54m 28.1s) | C | 15 | 17.5 |
609 | 2026-09-26 16:30:01 | MASTER-Tunka | (01h 18m 17.43s , +64d 54m 28.1s) | C | 45 | 18.0 | Coadd
613 | 2026-09-26 16:30:19 | MASTER-Tunka | (01h 17m 01.17s , +65d 03m 24.3s) | C | 15 | 17.2 |
613 | 2026-09-26 16:30:19 | MASTER-Tunka | (01h 18m 17.34s , +64d 54m 27.5s) | C | 15 | 17.3 |
632 | 2026-09-26 16:30:38 | MASTER-Tunka | (01h 17m 01.10s , +65d 03m 23.7s) | C | 15 | 17.2 |
632 | 2026-09-26 16:30:38 | MASTER-Tunka | (01h 18m 17.26s , +64d 54m 26.9s) | C | 15 | 17.3 |
647 | 2026-09-26 16:30:56 | MASTER-Tunka | (01h 17m 01.03s , +65d 03m 23.0s) | C | 10 | 17.1 |
647 | 2026-09-26 16:30:56 | MASTER-Tunka | (01h 18m 17.21s , +64d 54m 26.3s) | C | 10 | 17.2 |
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