TITLE: GCN CIRCULAR NUMBER: 44406 SUBJECT: Fermi trigger No 798737427: Global MASTER-Net observations report DATE: 26/04/25 03:16:51 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-OAGH robotic telescope [1] located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB260424.65 (trigger No 798737427,11h 26m 57.60s , +20d 14m 24.0s, R=14.8) errorbox 41869 sec after notice time and 41891 sec after trigger time at 2026-04-25 03:08:33 UT, with upper limit up to 18.9 mag. Observations started at twilight. The observations began at zenith distance = 32 deg. The sun altitude is -16.0 deg. The galactic latitude b = 70 deg., longitude l = 229 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3269496 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 41921 | 2026-04-25 03:08:33 | MASTER-OAGH | (11h 47m 05.86s , +10d 42m 06.0s) | C | 60 | 18.6 | 41921 | 2026-04-25 03:08:33 | MASTER-OAGH | (11h 49m 08.48s , +10d 05m 44.8s) | C | 60 | 18.7 | 41994 | 2026-04-25 03:09:46 | MASTER-OAGH | (11h 55m 15.30s , +10d 43m 09.7s) | C | 60 | 18.6 | 41994 | 2026-04-25 03:09:46 | MASTER-OAGH | (11h 57m 17.68s , +10d 06m 46.1s) | C | 60 | 18.6 | 42066 | 2026-04-25 03:10:58 | MASTER-OAGH | (11h 43m 05.83s , +08d 46m 55.3s) | C | 60 | 18.8 | 42066 | 2026-04-25 03:10:58 | MASTER-OAGH | (11h 45m 07.84s , +08d 10m 31.3s) | C | 60 | 18.9 | 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/44406. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...