TITLE: GCN CIRCULAR NUMBER: 41945 SUBJECT: Fermi trigger No 780156732: Global MASTER-Net observations report DATE: 25/09/22 21:31:17 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB250921.59 (trigger No 780156732,20h 24m 04.08s , +00d 33m 00.0s, R=33.5) errorbox 42698 sec after notice time and 42707 sec after trigger time at 2025-09-22 02:03:54 UT, with upper limit up to 20.3 mag. The observations began at zenith distance = 26 deg. The sun altitude is -44.3 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB250921.59 errorbox 1 days 6573 sec after notice time and 1 days 6582 sec after trigger time at 2025-09-22 16:01:50 UT, with upper limit up to 17.7 mag. Observations started at twilight. The observations began at zenith distance = 38 deg. The sun altitude is -10.5 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB250921.59 errorbox 1 days 17595 sec after notice time and 1 days 17604 sec after trigger time at 2025-09-22 19:05:31 UT, with upper limit up to 19.4 mag. The observations began at zenith distance = 43 deg. The sun altitude is -32.0 deg. The galactic latitude b = -21 deg., longitude l = 45 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2996777 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 42737 | 2025-09-22 02:03:54 | MASTER-OAFA | (19h 50m 28.63s , -19d 46m 33.6s) | C | 60 | 19.6 | 42813 | 2025-09-22 02:05:10 | MASTER-OAFA | (19h 59m 04.47s , -19d 46m 40.4s) | C | 60 | 19.9 | 42985 | 2025-09-22 02:08:02 | MASTER-OAFA | (19h 50m 31.65s , -19d 46m 10.8s) | C | 60 | 19.6 | 43060 | 2025-09-22 02:09:17 | MASTER-OAFA | (19h 59m 05.00s , -19d 44m 57.1s) | C | 60 | 19.8 | 43229 | 2025-09-22 02:12:06 | MASTER-OAFA | (19h 50m 28.14s , -19d 44m 25.3s) | C | 60 | 19.6 | 43305 | 2025-09-22 02:13:22 | MASTER-OAFA | (19h 53m 08.47s , -17d 52m 34.7s) | C | 60 | 19.7 | 43381 | 2025-09-22 02:14:38 | MASTER-OAFA | (20h 01m 37.51s , -17d 52m 26.1s) | C | 60 | 19.9 | 43457 | 2025-09-22 02:15:54 | MASTER-OAFA | (19h 53m 11.41s , -17d 50m 53.1s) | C | 60 | 19.7 | 43532 | 2025-09-22 02:17:09 | MASTER-OAFA | (20h 01m 35.40s , -17d 52m 38.4s) | C | 60 | 19.9 | 43608 | 2025-09-22 02:18:25 | MASTER-OAFA | (19h 53m 15.09s , -17d 50m 57.3s) | C | 60 | 19.8 | 43692 | 2025-09-22 02:19:49 | MASTER-OAFA | (21h 04m 54.78s , -14d 06m 56.2s) | C | 60 | 20.2 | 43767 | 2025-09-22 02:21:05 | MASTER-OAFA | (21h 13m 04.77s , -14d 08m 17.9s) | C | 60 | 20.0 | 43843 | 2025-09-22 02:22:20 | MASTER-OAFA | (21h 04m 55.21s , -14d 07m 38.0s) | C | 60 | 20.1 | 43920 | 2025-09-22 02:23:37 | MASTER-OAFA | (21h 13m 07.40s , -14d 06m 29.2s) | C | 60 | 20.0 | 43996 | 2025-09-22 02:24:53 | MASTER-OAFA | (21h 04m 52.78s , -14d 07m 39.7s) | C | 60 | 20.1 | 44074 | 2025-09-22 02:26:12 | MASTER-OAFA | (21h 11m 50.89s , -23d 36m 50.4s) | C | 60 | 20.2 | 44150 | 2025-09-22 02:27:27 | MASTER-OAFA | (21h 20m 32.85s , -23d 36m 14.1s) | C | 60 | 20.1 | 44226 | 2025-09-22 02:28:44 | MASTER-OAFA | (21h 11m 57.12s , -23d 36m 47.6s) | C | 60 | 20.1 | 44302 | 2025-09-22 02:30:00 | MASTER-OAFA | (21h 20m 33.70s , -23d 38m 10.5s) | C | 60 | 20.1 | 44377 | 2025-09-22 02:31:15 | MASTER-OAFA | (21h 11m 56.17s , -23d 37m 33.3s) | C | 60 | 20.1 | 45719 | 2025-09-22 02:53:36 | MASTER-OAFA | (21h 41m 12.76s , -29d 09m 13.2s) | C | 60 | 20.2 | 45873 | 2025-09-22 02:56:10 | MASTER-OAFA | (21h 41m 10.27s , -29d 08m 40.6s) | C | 60 | 20.3 | 46022 | 2025-09-22 02:58:40 | MASTER-OAFA | (21h 41m 16.52s , -29d 08m 42.0s) | C | 60 | 20.3 | 49433 | 2025-09-22 03:55:30 | MASTER-OAFA | (21h 20m 37.25s , -23d 35m 53.7s) | C | 60 | 20.1 | 49589 | 2025-09-22 03:58:07 | MASTER-OAFA | (21h 20m 36.58s , -23d 36m 52.5s) | C | 60 | 20.0 | 49744 | 2025-09-22 04:00:42 | MASTER-OAFA | (21h 20m 40.36s , -23d 35m 16.2s) | C | 60 | 20.1 | 49907 | 2025-09-22 04:03:24 | MASTER-OAFA | (21h 41m 27.25s , -29d 17m 23.8s) | C | 60 | 20.2 | 49982 | 2025-09-22 04:04:39 | MASTER-OAFA | (21h 41m 21.20s , -29d 18m 22.1s) | C | 60 | 20.1 | 50059 | 2025-09-22 04:05:56 | MASTER-OAFA | (21h 41m 20.91s , -29d 17m 20.7s) | C | 60 | 20.2 | 93012 | 2025-09-22 16:01:50 | MASTER-Kislovodsk | (19h 09m 53.50s , +05d 21m 18.7s) | C | 60 | 16.7 | 93012 | 2025-09-22 16:01:50 | MASTER-Kislovodsk | (19h 10m 08.91s , +04d 56m 58.0s) | C | 60 | 16.9 | 96648 | 2025-09-22 17:02:26 | MASTER-Kislovodsk | (19h 11m 04.53s , +05d 11m 24.6s) | C | 60 | 16.9 | 96648 | 2025-09-22 17:02:26 | MASTER-Kislovodsk | (19h 10m 54.81s , +05d 34m 26.2s) | C | 60 | 17.7 | 104034 | 2025-09-22 19:05:31 | MASTER-SAAO | (22h 42m 26.01s , -01d 06m 41.5s) | C | 60 | 19.2 | 104034 | 2025-09-22 19:05:31 | MASTER-SAAO | (22h 40m 35.17s , -00d 51m 17.4s) | C | 60 | 19.3 | 104131 | 2025-09-22 19:07:08 | MASTER-SAAO | (22h 42m 35.06s , +00d 47m 13.4s) | C | 60 | 19.4 | 104131 | 2025-09-22 19:07:08 | MASTER-SAAO | (22h 40m 44.35s , +01d 02m 37.1s) | C | 60 | 19.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/41945. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...