TITLE: GCN CIRCULAR NUMBER: 39552 SUBJECT: Fermi GRB 250302A: Global MASTER-Net observations report DATE: 25/03/02 21:33:42 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs lipunov@xray.sai.msu.ru

V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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 (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 250302A ( Fermi GBM team, GCN 39548) errorbox 21539 sec after notice time and 21575 sec after trigger time at 2025-03-02 19:46:08 UT, with upper limit up to 20.4 mag. The observations began at zenith distance = 43 deg. The sun altitude is -36.5 deg.

MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 250302A errorbox 22677 sec after notice time and 22713 sec after trigger time at 2025-03-02 20:05:06 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 77 deg. The sun altitude is -50.2 deg.

The galactic latitude b = 46 deg., longitude l = 22 deg.

Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2796892

We obtain a following upper limits.

Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________

21605 | 2025-03-02 19:46:08 | MASTER-Tunka | (15h 31m 17.49s , +16d 30m 25.9s) | C | 60 | 19.8 | 21665 | 2025-03-02 19:46:08 | MASTER-Tunka | (15h 31m 17.49s , +16d 30m 25.9s) | C | 180 | 20.3 | Coadd 21678 | 2025-03-02 19:47:20 | MASTER-Tunka | (15h 39m 40.44s , +16d 31m 15.0s) | C | 60 | 19.8 | 21738 | 2025-03-02 19:47:20 | MASTER-Tunka | (15h 39m 40.44s , +16d 31m 14.9s) | C | 180 | 20.3 | Coadd 22064 | 2025-03-02 19:53:47 | MASTER-Tunka | (15h 41m 02.12s , +18d 25m 27.9s) | C | 60 | 19.8 | 22124 | 2025-03-02 19:53:47 | MASTER-Tunka | (15h 41m 02.11s , +18d 25m 27.9s) | C | 180 | 20.4 | Coadd 22137 | 2025-03-02 19:55:00 | MASTER-Tunka | (15h 49m 28.20s , +18d 23m 04.7s) | C | 60 | 19.7 | 22197 | 2025-03-02 19:55:00 | MASTER-Tunka | (15h 49m 28.20s , +18d 23m 04.6s) | C | 180 | 20.3 | Coadd 22210 | 2025-03-02 19:56:13 | MASTER-Tunka | (15h 31m 19.81s , +16d 32m 30.0s) | C | 60 | 19.9 | 22283 | 2025-03-02 19:57:25 | MASTER-Tunka | (15h 39m 34.02s , +16d 30m 56.3s) | C | 60 | 19.9 | 22586 | 2025-03-02 20:02:28 | MASTER-Tunka | (15h 23m 46.12s , +16d 31m 47.0s) | C | 60 | 20.0 | 22646 | 2025-03-02 20:02:28 | MASTER-Tunka | (15h 23m 46.12s , +16d 31m 47.0s) | C | 180 | 20.3 | Coadd 22744 | 2025-03-02 20:05:06 | MASTER-Kislovodsk | (15h 31m 05.90s , +18d 24m 03.2s) | C | 60 | 13.6 | 22820 | 2025-03-02 20:06:23 | MASTER-Tunka | (15h 40m 59.24s , +18d 26m 16.1s) | C | 60 | 19.8 | 22823 | 2025-03-02 20:06:26 | MASTER-Kislovodsk | (15h 20m 24.78s , +14d 35m 08.1s) | C | 60 | 14.4 | 22893 | 2025-03-02 20:07:36 | MASTER-Tunka | (15h 49m 30.08s , +18d 24m 37.9s) | C | 60 | 19.8 | 22904 | 2025-03-02 20:07:46 | MASTER-Kislovodsk | (15h 28m 43.31s , +14d 36m 18.2s) | C | 60 | 13.6 | 22967 | 2025-03-02 20:08:49 | MASTER-Tunka | (15h 31m 14.39s , +16d 31m 14.0s) | C | 60 | 19.8 | 23042 | 2025-03-02 20:10:04 | MASTER-Tunka | (15h 39m 39.86s , +16d 31m 01.5s) | C | 60 | 19.7 | 23160 | 2025-03-02 20:12:03 | MASTER-Kislovodsk | (15h 36m 12.34s , +14d 34m 34.1s) | C | 60 | 15.6 | 23240 | 2025-03-02 20:13:23 | MASTER-Kislovodsk | (15h 44m 23.73s , +14d 35m 43.7s) | C | 60 | 14.7 | 23337 | 2025-03-02 20:14:59 | MASTER-Tunka | (15h 23m 42.86s , +16d 33m 11.8s) | C | 60 | 19.9 | 23413 | 2025-03-02 20:16:15 | MASTER-Tunka | (15h 30m 58.44s , +12d 44m 41.7s) | C | 60 | 19.8 | 23473 | 2025-03-02 20:16:15 | MASTER-Tunka | (15h 30m 58.44s , +12d 44m 41.7s) | C | 180 | 20.1 | Coadd 23480 | 2025-03-02 20:17:22 | MASTER-Kislovodsk | (15h 31m 02.91s , +18d 23m 56.7s) | C | 60 | 16.9 | 23486 | 2025-03-02 20:17:29 | MASTER-Tunka | (15h 39m 05.45s , +12d 43m 05.6s) | C | 60 | 19.7 | 23546 | 2025-03-02 20:17:29 | MASTER-Tunka | (15h 39m 05.45s , +12d 43m 05.5s) | C | 180 | 20.1 | Coadd 23560 | 2025-03-02 20:18:42 | MASTER-Kislovodsk | (15h 20m 23.76s , +14d 37m 26.2s) | C | 60 | 17.0 | 23561 | 2025-03-02 20:18:43 | MASTER-Tunka | (15h 41m 05.86s , +18d 25m 13.1s) | C | 60 | 19.8 | 23637 | 2025-03-02 20:19:59 | MASTER-Tunka | (15h 49m 27.79s , +18d 25m 54.4s) | C | 60 | 19.7 | 23639 | 2025-03-02 20:20:02 | MASTER-Kislovodsk | (15h 28m 43.11s , +14d 36m 08.7s) | C | 60 | 16.8 | 23712 | 2025-03-02 20:21:15 | MASTER-Tunka | (15h 31m 16.75s , +16d 31m 55.3s) | C | 60 | 19.9 | 23772 | 2025-03-02 20:21:15 | MASTER-Tunka | (15h 31m 16.75s , +16d 31m 55.1s) | C | 180 | 19.8 | Coadd 23785 | 2025-03-02 20:22:27 | MASTER-Tunka | (15h 39m 40.80s , +16d 32m 51.7s) | C | 60 | 19.8 | 23799 | 2025-03-02 20:22:42 | MASTER-Kislovodsk | (15h 21m 17.81s , +12d 41m 36.6s) | C | 60 | 17.1 | 23959 | 2025-03-02 20:25:22 | MASTER-Kislovodsk | (15h 36m 07.19s , +14d 35m 28.8s) | C | 60 | 17.1 | 24039 | 2025-03-02 20:26:41 | MASTER-Kislovodsk | (15h 44m 26.50s , +14d 36m 37.5s) | C | 60 | 17.0 | 24080 | 2025-03-02 20:27:23 | MASTER-Tunka | (15h 23m 42.84s , +16d 32m 51.8s) | C | 60 | 19.9 | 24154 | 2025-03-02 20:28:37 | MASTER-Tunka | (15h 30m 58.25s , +12d 44m 31.8s) | C | 60 | 19.7 | 24230 | 2025-03-02 20:29:53 | MASTER-Tunka | (15h 39m 07.48s , +12d 45m 31.1s) | C | 60 | 19.7 | 24278 | 2025-03-02 20:30:40 | MASTER-Kislovodsk | (15h 31m 07.61s , +18d 24m 25.8s) | C | 60 | 17.4 | 24305 | 2025-03-02 20:31:07 | MASTER-Tunka | (15h 41m 01.62s , +18d 25m 42.8s) | C | 60 | 19.8 | 24365 | 2025-03-02 20:31:07 | MASTER-Tunka | (15h 41m 01.62s , +18d 25m 42.8s) | C | 180 | 20.2 | Coadd 24749 | 2025-03-02 20:38:31 | MASTER-Tunka | (15h 30m 53.25s , +16d 35m 14.6s) | C | 60 | 19.9 | 24939 | 2025-03-02 20:41:41 | MASTER-Kislovodsk | (15h 21m 11.94s , +12d 41m 22.0s) | C | 60 | 17.7 | 25098 | 2025-03-02 20:44:21 | MASTER-Kislovodsk | (15h 36m 07.54s , +14d 36m 59.1s) | C | 60 | 17.5 | 25178 | 2025-03-02 20:45:41 | MASTER-Kislovodsk | (15h 44m 23.92s , +14d 35m 10.2s) | C | 60 | 17.4 | 25423 | 2025-03-02 20:49:46 | MASTER-Tunka | (15h 23m 44.45s , +16d 35m 47.7s) | C | 60 | 20.0 | 25497 | 2025-03-02 20:50:59 | MASTER-Tunka | (15h 30m 54.18s , +12d 45m 40.7s) | C | 60 | 19.9 | 25569 | 2025-03-02 20:52:11 | MASTER-Tunka | (15h 39m 10.58s , +12d 46m 23.3s) | C | 60 | 19.8 | 25643 | 2025-03-02 20:53:25 | MASTER-Tunka | (15h 40m 57.76s , +18d 27m 42.0s) | C | 60 | 20.0 | 25715 | 2025-03-02 20:54:38 | MASTER-Tunka | (15h 49m 22.96s , +18d 28m 04.2s) | C | 60 | 19.8 | 25788 | 2025-03-02 20:55:51 | MASTER-Tunka | (15h 31m 18.68s , +16d 34m 38.3s) | C | 60 | 19.8 | 25861 | 2025-03-02 20:57:04 | MASTER-Tunka | (15h 39m 32.28s , +16d 33m 01.3s) | C | 60 | 19.8 | 26164 | 2025-03-02 21:02:06 | MASTER-Tunka | (15h 23m 47.97s , +16d 36m 20.0s) | C | 60 | 19.7 | 26237 | 2025-03-02 21:03:20 | MASTER-Tunka | (15h 30m 50.25s , +12d 47m 05.1s) | C | 60 | 19.6 | 26311 | 2025-03-02 21:04:33 | MASTER-Tunka | (15h 39m 02.80s , +12d 47m 29.2s) | C | 60 | 19.5 | 26385 | 2025-03-02 21:05:48 | MASTER-Tunka | (15h 41m 03.56s , +18d 28m 19.9s) | C | 60 | 18.6 | 26460 | 2025-03-02 21:07:03 | MASTER-Tunka | (15h 46m 29.50s , +12d 46m 38.1s) | C | 60 | 19.8 | 26537 | 2025-03-02 21:08:19 | MASTER-Tunka | (15h 54m 41.53s , +12d 44m 47.4s) | C | 60 | 19.8 | 26838 | 2025-03-02 21:13:21 | MASTER-Tunka | (15h 23m 46.02s , +16d 36m 09.2s) | C | 60 | 20.1 | 26914 | 2025-03-02 21:14:37 | MASTER-Tunka | (15h 30m 49.86s , +12d 46m 41.0s) | C | 60 | 20.0 | 27078 | 2025-03-02 21:17:20 | MASTER-Tunka | (15h 39m 08.10s , +12d 47m 46.3s) | C | 60 | 20.0 | 27150 | 2025-03-02 21:18:33 | MASTER-Tunka | (15h 46m 26.15s , +12d 46m 38.9s) | C | 60 | 20.0 | 27222 | 2025-03-02 21:19:44 | MASTER-Tunka | (15h 54m 37.57s , +12d 47m 02.5s) | C | 60 | 20.0 | 27300 | 2025-03-02 21:21:02 | MASTER-Tunka | (15h 38m 21.62s , +14d 40m 25.5s) | C | 60 | 20.1 | 27373 | 2025-03-02 21:22:15 | MASTER-Tunka | (15h 46m 43.50s , +14d 39m 54.8s) | C | 60 | 20.1 | 27442 | 2025-03-02 21:23:24 | MASTER-Tunka | (15h 55m 28.03s , +10d 51m 13.2s) | C | 60 | 20.0 | Filter C is a clear (unfiltred) band.

The observation and reduction will continue. The message may be cited.

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