TITLE: GCN CIRCULAR NUMBER: 42831 SUBJECT: Fermi GRB 251125A: Global MASTER-Net observations report DATE: 25/11/25 01:15:21 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-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 251125A ( Fermi GBM team, GCN 42830) errorbox 29 sec after notice time and 35 sec after trigger time at 2025-11-25 01:00:14 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 58 deg. The sun altitude is -35.2 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 251125A errorbox 58 sec after notice time and 64 sec after trigger time at 2025-11-25 01:00:43 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 65 deg. The sun altitude is -25.5 deg. The galactic latitude b = 44 deg., longitude l = 259 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3051146 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 40 | 2025-11-25 01:00:14 | MASTER-Kislovodsk | (10h 47m 41.84s , -02d 16m 18.0s) | C | 10 | 16.6 | 69 | 2025-11-25 01:00:43 | MASTER-SAAO | (10h 46m 14.24s , -02d 25m 57.0s) | C | 10 | 17.6 | 69 | 2025-11-25 01:00:43 | MASTER-SAAO | (10h 48m 05.24s , -02d 41m 35.6s) | C | 10 | 17.7 | 70 | 2025-11-25 01:00:44 | MASTER-Kislovodsk | (10h 47m 41.88s , -02d 16m 25.2s) | C | 10 | 16.7 | 103 | 2025-11-25 01:01:12 | MASTER-SAAO | (10h 46m 14.21s , -02d 25m 59.4s) | C | 20 | 18.1 | 103 | 2025-11-25 01:01:12 | MASTER-SAAO | (10h 48m 05.20s , -02d 41m 35.0s) | C | 20 | 18.5 | 106 | 2025-11-25 01:01:14 | MASTER-Kislovodsk | (10h 47m 41.94s , -02d 16m 40.7s) | C | 20 | 17.2 | 147 | 2025-11-25 01:01:51 | MASTER-SAAO | (10h 46m 14.28s , -02d 25m 58.7s) | C | 30 | 18.5 | 147 | 2025-11-25 01:01:51 | MASTER-SAAO | (10h 48m 05.23s , -02d 41m 33.9s) | C | 30 | 18.8 | 146 | 2025-11-25 01:01:54 | MASTER-Kislovodsk | (10h 47m 41.97s , -02d 16m 43.6s) | C | 20 | 17.2 | 181 | 2025-11-25 01:01:54 | MASTER-Kislovodsk | (10h 47m 41.96s , -02d 16m 43.7s) | C | 90 | 18.2 | Coadd 195 | 2025-11-25 01:02:38 | MASTER-Kislovodsk | (10h 47m 41.94s , -02d 16m 44.6s) | C | 30 | 17.5 | 201 | 2025-11-25 01:02:40 | MASTER-SAAO | (10h 46m 14.26s , -02d 25m 58.4s) | C | 40 | 18.8 | 201 | 2025-11-25 01:02:40 | MASTER-SAAO | (10h 48m 05.20s , -02d 41m 33.1s) | C | 40 | 18.9 | 250 | 2025-11-25 01:03:28 | MASTER-Kislovodsk | (10h 47m 41.92s , -02d 16m 45.1s) | C | 40 | 17.8 | 265 | 2025-11-25 01:03:39 | MASTER-SAAO | (10h 46m 14.24s , -02d 25m 58.5s) | C | 50 | 18.9 | 265 | 2025-11-25 01:03:39 | MASTER-SAAO | (10h 48m 05.17s , -02d 41m 32.9s) | C | 50 | 19.0 | 315 | 2025-11-25 01:04:28 | MASTER-Kislovodsk | (10h 47m 41.90s , -02d 16m 45.0s) | C | 50 | 17.8 | 315 | 2025-11-25 01:04:28 | MASTER-Kislovodsk | (10h 52m 01.99s , -02d 40m 47.8s) | C | 50 | 12.0 | 340 | 2025-11-25 01:04:48 | MASTER-SAAO | (10h 46m 14.20s , -02d 25m 58.8s) | C | 60 | 19.1 | 340 | 2025-11-25 01:04:48 | MASTER-SAAO | (10h 48m 05.12s , -02d 41m 32.9s) | C | 60 | 19.3 | 395 | 2025-11-25 01:05:38 | MASTER-Kislovodsk | (10h 47m 41.86s , -02d 16m 44.4s) | C | 70 | 18.1 | 480 | 2025-11-25 01:07:08 | MASTER-Kislovodsk | (10h 51m 53.78s , -02d 19m 53.0s) | C | 60 | 17.8 | 560 | 2025-11-25 01:08:28 | MASTER-Kislovodsk | (10h 51m 23.73s , -00d 26m 51.2s) | C | 60 | 18.0 | 639 | 2025-11-25 01:09:48 | MASTER-Kislovodsk | (10h 36m 38.70s , -02d 21m 11.9s) | C | 60 | 17.0 | 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/42831. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...