TITLE: GCN CIRCULAR NUMBER: 43954 SUBJECT: Fermi GRB 260310A: Global MASTER-Net observations report DATE: 26/03/10 16:32:56 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> 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 260310A ( Fermi GBM team, GCN 43951) errorbox 39832 sec after notice time and 39865 sec after trigger time at 2026-03-10 16:01:36 UT, with upper limit up to 20.0 mag. The observations began at zenith distance = 36 deg. The sun altitude is -40.5 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 260310A errorbox 40477 sec after notice time and 40510 sec after trigger time at 2026-03-10 16:12:21 UT, with upper limit up to 18.3 mag. Observations started at twilight. The observations began at zenith distance = 51 deg. The sun altitude is -12.2 deg. The galactic latitude b = 38 deg., longitude l = 118 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3178578 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 39895 | 2026-03-10 16:01:36 | MASTER-Tunka | (14h 43m 00.89s , +78d 55m 32.9s) | C | 60 | 19.9 | 39895 | 2026-03-10 16:01:36 | MASTER-Tunka | (14h 45m 33.78s , +78d 47m 59.9s) | C | 60 | 20.0 | 40197 | 2026-03-10 16:06:37 | MASTER-Tunka | (14h 33m 24.43s , +80d 47m 57.5s) | C | 60 | 19.1 | 40197 | 2026-03-10 16:06:37 | MASTER-Tunka | (14h 36m 13.25s , +80d 42m 38.1s) | C | 60 | 19.2 | 40540 | 2026-03-10 16:12:21 | MASTER-Kislovodsk | (13h 26m 03.01s , +78d 44m 12.4s) | C | 60 | 17.9 | 40643 | 2026-03-10 16:14:03 | MASTER-Kislovodsk | (14h 10m 06.46s , +76d 46m 16.8s) | C | 60 | 17.8 | 40749 | 2026-03-10 16:15:49 | MASTER-Kislovodsk | (14h 29m 09.94s , +78d 40m 44.7s) | C | 60 | 18.1 | 40850 | 2026-03-10 16:17:31 | MASTER-Kislovodsk | (13h 41m 13.66s , +80d 36m 24.9s) | C | 60 | 18.3 | 40941 | 2026-03-10 16:19:01 | MASTER-Kislovodsk | (13h 56m 38.66s , +74d 54m 16.8s) | C | 60 | 18.0 | 41046 | 2026-03-10 16:20:47 | MASTER-Kislovodsk | (14h 57m 06.59s , +80d 32m 41.8s) | C | 60 | 18.3 | 41150 | 2026-03-10 16:22:30 | MASTER-Kislovodsk | (15h 03m 52.45s , +76d 43m 39.0s) | C | 60 | 17.9 | 41357 | 2026-03-10 16:25:57 | MASTER-Kislovodsk | (14h 46m 01.37s , +74d 52m 17.5s) | C | 60 | 14.0 | 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/43954. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...