[vsnet-grb-info 38093] Fermi GRB 250404A: Global MASTER-Net observations report

TITLE: GCN CIRCULAR NUMBER: 40070 SUBJECT: Fermi GRB 250404A: Global MASTER-Net observations report DATE: 25/04/05 00:17:01 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 250404A ( Fermi GBM team, GCN 40050) errorbox 16599 sec after notice time and 16639 sec after trigger time at 2025-04-04 18:57:05 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 66 deg. The sun altitude is -28.6 deg.

MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 250404A errorbox 31880 sec after notice time and 31919 sec after trigger time at 2025-04-04 23:11:46 UT, with upper limit up to 19.3 mag. Observations started at twilight. The observations began at zenith distance = 67 deg. The sun altitude is -10.4 deg.

The galactic latitude b = 32 deg., longitude l = 188 deg.

Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2832903

We obtain a following upper limits.

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

16669 | 2025-04-04 18:57:05 | MASTER-Tunka | (08h 19m 51.88s , +36d 00m 34.0s) | C | 60 | 18.6 | 16729 | 2025-04-04 18:57:05 | MASTER-Tunka | (08h 19m 51.88s , +36d 00m 34.0s) | C | 180 | 19.3 | Coadd 16740 | 2025-04-04 18:58:16 | MASTER-Tunka | (08h 19m 58.07s , +36d 00m 34.7s) | C | 60 | 18.6 | 16812 | 2025-04-04 18:59:28 | MASTER-Tunka | (08h 19m 55.11s , +36d 02m 04.0s) | C | 60 | 18.6 | 16885 | 2025-04-04 19:00:41 | MASTER-Tunka | (08h 19m 55.07s , +36d 00m 32.5s) | C | 60 | 18.7 | 16945 | 2025-04-04 19:00:41 | MASTER-Tunka | (08h 19m 55.07s , +36d 00m 32.5s) | C | 180 | 19.4 | Coadd 16962 | 2025-04-04 19:01:58 | MASTER-Tunka | (08h 19m 57.66s , +36d 02m 04.7s) | C | 60 | 18.6 | 17033 | 2025-04-04 19:03:09 | MASTER-Tunka | (08h 19m 52.37s , +36d 01m 15.7s) | C | 60 | 18.7 | 17108 | 2025-04-04 19:04:24 | MASTER-Tunka | (08h 19m 51.30s , +36d 02m 12.7s) | C | 60 | 18.7 | 17168 | 2025-04-04 19:04:24 | MASTER-Tunka | (08h 19m 51.30s , +36d 02m 12.8s) | C | 180 | 19.5 | Coadd 17393 | 2025-04-04 19:09:09 | MASTER-Tunka | (08h 19m 52.28s , +35d 59m 59.8s) | C | 60 | 18.7 | 17466 | 2025-04-04 19:10:22 | MASTER-Tunka | (08h 19m 58.20s , +36d 00m 10.2s) | C | 60 | 18.7 | 17540 | 2025-04-04 19:11:35 | MASTER-Tunka | (08h 19m 54.28s , +36d 01m 24.3s) | C | 60 | 18.7 | 17600 | 2025-04-04 19:11:35 | MASTER-Tunka | (08h 19m 54.28s , +36d 01m 24.2s) | C | 180 | 19.4 | Coadd 17612 | 2025-04-04 19:12:48 | MASTER-Tunka | (08h 19m 54.27s , +35d 59m 56.4s) | C | 60 | 18.6 | 17683 | 2025-04-04 19:13:59 | MASTER-Tunka | (08h 19m 57.20s , +36d 01m 34.1s) | C | 60 | 18.6 | 17756 | 2025-04-04 19:15:12 | MASTER-Tunka | (08h 19m 51.23s , +36d 00m 41.3s) | C | 60 | 18.5 | 17816 | 2025-04-04 19:15:12 | MASTER-Tunka | (08h 19m 51.23s , +36d 00m 41.3s) | C | 180 | 19.3 | Coadd 17829 | 2025-04-04 19:16:24 | MASTER-Tunka | (08h 19m 51.76s , +36d 01m 37.4s) | C | 60 | 18.6 | 17903 | 2025-04-04 19:17:39 | MASTER-Tunka | (08h 19m 57.64s , +36d 00m 34.5s) | C | 60 | 18.7 | 17975 | 2025-04-04 19:18:51 | MASTER-Tunka | (08h 19m 51.82s , +35d 59m 30.3s) | C | 60 | 18.6 | 18035 | 2025-04-04 19:18:51 | MASTER-Tunka | (08h 19m 51.82s , +35d 59m 30.3s) | C | 180 | 19.4 | Coadd 18048 | 2025-04-04 19:20:04 | MASTER-Tunka | (08h 19m 57.26s , +35d 59m 42.1s) | C | 60 | 18.6 | 18120 | 2025-04-04 19:21:16 | MASTER-Tunka | (08h 19m 53.77s , +36d 01m 07.0s) | C | 60 | 18.5 | 18192 | 2025-04-04 19:22:28 | MASTER-Tunka | (08h 19m 53.78s , +35d 59m 24.2s) | C | 60 | 18.6 | 18252 | 2025-04-04 19:22:28 | MASTER-Tunka | (08h 19m 53.78s , +35d 59m 24.1s) | C | 180 | 19.4 | Coadd 18263 | 2025-04-04 19:23:39 | MASTER-Tunka | (08h 19m 57.55s , +36d 00m 59.3s) | C | 60 | 18.7 | 18337 | 2025-04-04 19:24:53 | MASTER-Tunka | (08h 19m 50.49s , +36d 00m 11.6s) | C | 60 | 18.6 | 31925 | 2025-04-04 23:11:46 | MASTER-OAFA | (08h 08m 19.47s , +34d 59m 12.3s) | C | 10 | 14.9 | 31925 | 2025-04-04 23:11:46 | MASTER-OAFA | (08h 19m 21.81s , +35d 21m 51.8s) | C | 10 | 16.5 | 31967 | 2025-04-04 23:12:28 | MASTER-OAFA | (08h 08m 15.18s , +35d 00m 30.7s) | C | 10 | 14.9 | 31967 | 2025-04-04 23:12:28 | MASTER-OAFA | (08h 19m 17.72s , +35d 23m 08.7s) | C | 10 | 16.6 | 32005 | 2025-04-04 23:13:06 | MASTER-OAFA | (08h 08m 15.01s , +34d 58m 38.5s) | C | 10 | 14.9 | 32005 | 2025-04-04 23:13:06 | MASTER-OAFA | (08h 19m 17.32s , +35d 21m 15.2s) | C | 10 | 16.7 | 32044 | 2025-04-04 23:13:45 | MASTER-OAFA | (08h 08m 17.35s , +35d 00m 09.4s) | C | 10 | 15.1 | 32044 | 2025-04-04 23:13:45 | MASTER-OAFA | (08h 19m 19.90s , +35d 22m 45.2s) | C | 10 | 16.8 | 32086 | 2025-04-04 23:14:27 | MASTER-OAFA | (08h 08m 10.02s , +34d 59m 29.2s) | C | 10 | 15.2 | 32086 | 2025-04-04 23:14:27 | MASTER-OAFA | (08h 19m 12.52s , +35d 22m 04.1s) | C | 10 | 16.8 | 32127 | 2025-04-04 23:15:08 | MASTER-OAFA | (08h 08m 11.16s , +35d 00m 25.4s) | C | 10 | 15.2 | 32127 | 2025-04-04 23:15:08 | MASTER-OAFA | (08h 19m 13.83s , +35d 22m 59.5s) | C | 10 | 16.8 | 32165 | 2025-04-04 23:15:45 | MASTER-OAFA | (08h 08m 16.58s , +34d 59m 22.6s) | C | 10 | 15.3 | 32165 | 2025-04-04 23:15:46 | MASTER-OAFA | (08h 19m 19.15s , +35d 21m 56.2s) | C | 10 | 17.0 | 32204 | 2025-04-04 23:16:24 | MASTER-OAFA | (08h 08m 09.70s , +34d 58m 17.6s) | C | 10 | 15.3 | 32204 | 2025-04-04 23:16:25 | MASTER-OAFA | (08h 19m 12.12s , +35d 20m 50.5s) | C | 10 | 16.9 | 32241 | 2025-04-04 23:17:02 | MASTER-OAFA | (08h 08m 15.41s , +34d 58m 44.1s) | C | 10 | 15.3 | 32241 | 2025-04-04 23:17:02 | MASTER-OAFA | (08h 19m 17.91s , +35d 21m 16.7s) | C | 10 | 17.0 | 32280 | 2025-04-04 23:17:41 | MASTER-OAFA | (08h 08m 11.54s , +35d 00m 01.8s) | C | 10 | 15.3 | 32280 | 2025-04-04 23:17:41 | MASTER-OAFA | (08h 19m 14.23s , +35d 22m 33.8s) | C | 10 | 17.0 | 32318 | 2025-04-04 23:18:19 | MASTER-OAFA | (08h 08m 11.34s , +34d 58m 27.0s) | C | 10 | 15.3 | 32318 | 2025-04-04 23:18:19 | MASTER-OAFA | (08h 19m 13.81s , +35d 20m 58.4s) | C | 10 | 17.1 | 32356 | 2025-04-04 23:18:57 | MASTER-OAFA | (08h 08m 13.99s , +34d 59m 41.3s) | C | 10 | 15.4 | 32357 | 2025-04-04 23:18:57 | MASTER-OAFA | (08h 19m 16.67s , +35d 22m 12.7s) | C | 10 | 17.2 | 33140 | 2025-04-04 23:32:01 | MASTER-OAFA | (08h 07m 59.46s , +34d 58m 26.5s) | C | 10 | 15.7 | 33150 | 2025-04-04 23:32:01 | MASTER-OAFA | (08h 19m 01.71s , +35d 21m 07.7s) | C | 30 | 18.4 | 33186 | 2025-04-04 23:32:47 | MASTER-OAFA | (08h 07m 58.57s , +34d 59m 30.7s) | C | 10 | 15.8 | 33197 | 2025-04-04 23:32:47 | MASTER-OAFA | (08h 19m 01.06s , +35d 22m 10.1s) | C | 30 | 18.4 | 33235 | 2025-04-04 23:33:35 | MASTER-OAFA | (08h 08m 03.56s , +34d 58m 34.6s) | C | 10 | 15.8 | 33245 | 2025-04-04 23:33:36 | MASTER-OAFA | (08h 19m 05.95s , +35d 21m 12.1s) | C | 30 | 18.5 | 33280 | 2025-04-04 23:34:21 | MASTER-OAFA | (08h 07m 56.35s , +34d 57m 37.5s) | C | 10 | 15.8 | 33290 | 2025-04-04 23:34:21 | MASTER-OAFA | (08h 18m 58.65s , +35d 20m 14.0s) | C | 30 | 18.4 | 33328 | 2025-04-04 23:35:09 | MASTER-OAFA | (08h 08m 02.36s , +34d 58m 09.7s) | C | 10 | 15.9 | 33338 | 2025-04-04 23:35:09 | MASTER-OAFA | (08h 19m 04.81s , +35d 20m 45.1s) | C | 30 | 18.6 | 33373 | 2025-04-04 23:35:54 | MASTER-OAFA | (08h 07m 58.28s , +34d 59m 32.8s) | C | 10 | 15.8 | 33384 | 2025-04-04 23:35:54 | MASTER-OAFA | (08h 19m 00.96s , +35d 22m 07.7s) | C | 30 | 18.5 | 33424 | 2025-04-04 23:36:45 | MASTER-OAFA | (08h 07m 57.86s , +34d 58m 00.1s) | C | 10 | 15.8 | 33434 | 2025-04-04 23:36:45 | MASTER-OAFA | (08h 19m 00.34s , +35d 20m 33.9s) | C | 30 | 18.5 | 33464 | 2025-04-04 23:36:45 | MASTER-OAFA | (08h 19m 00.33s , +35d 20m 33.8s) | C | 90 | 19.3 | Coadd 33471 | 2025-04-04 23:37:32 | MASTER-OAFA | (08h 08m 01.00s , +34d 59m 22.3s) | C | 10 | 15.8 | 33481 | 2025-04-04 23:37:32 | MASTER-OAFA | (08h 19m 03.70s , +35d 21m 55.5s) | C | 30 | 18.5 | 33519 | 2025-04-04 23:38:20 | MASTER-OAFA | (08h 07m 54.12s , +34d 58m 51.0s) | C | 10 | 15.9 | 33529 | 2025-04-04 23:38:20 | MASTER-OAFA | (08h 18m 56.76s , +35d 21m 23.8s) | C | 30 | 18.5 | 33566 | 2025-04-04 23:39:07 | MASTER-OAFA | (08h 07m 52.92s , +34d 59m 53.3s) | C | 10 | 15.9 | 33576 | 2025-04-04 23:39:07 | MASTER-OAFA | (08h 18m 55.71s , +35d 22m 25.5s) | C | 30 | 18.5 | 33606 | 2025-04-04 23:39:07 | MASTER-OAFA | (08h 18m 55.72s , +35d 22m 25.5s) | C | 90 | 19.3 | Coadd 33613 | 2025-04-04 23:39:54 | MASTER-OAFA | (08h 07m 58.66s , +34d 58m 55.1s) | C | 10 | 15.9 | 33624 | 2025-04-04 23:39:54 | MASTER-OAFA | (08h 19m 01.35s , +35d 21m 27.0s) | C | 30 | 18.5 | 33659 | 2025-04-04 23:40:40 | MASTER-OAFA | (08h 07m 51.06s , +34d 57m 56.5s) | C | 10 | 15.9 | 33669 | 2025-04-04 23:40:40 | MASTER-OAFA | (08h 18m 53.65s , +35d 20m 28.1s) | C | 30 | 18.4 | 33721 | 2025-04-04 23:41:27 | MASTER-OAFA | (08h 07m 56.45s , +34d 58m 08.6s) | C | 40 | 16.6 | 33731 | 2025-04-04 23:41:27 | MASTER-OAFA | (08h 18m 59.04s , +35d 20m 38.8s) | C | 60 | 18.4 | 33799 | 2025-04-04 23:42:45 | MASTER-OAFA | (08h 07m 52.46s , +34d 59m 53.5s) | C | 40 | 16.6 | 33809 | 2025-04-04 23:42:45 | MASTER-OAFA | (08h 18m 55.24s , +35d 22m 22.0s) | C | 60 | 18.6 | 33874 | 2025-04-04 23:44:00 | MASTER-OAFA | (08h 07m 51.72s , +34d 58m 08.4s) | C | 40 | 16.5 | 33885 | 2025-04-04 23:44:00 | MASTER-OAFA | (08h 18m 54.29s , +35d 20m 36.9s) | C | 60 | 18.6 | 33950 | 2025-04-04 23:45:16 | MASTER-OAFA | (08h 07m 52.58s , +34d 59m 42.2s) | C | 40 | 16.6 | 33961 | 2025-04-04 23:45:16 | MASTER-OAFA | (08h 18m 55.38s , +35d 22m 10.2s) | C | 60 | 18.6 | 34029 | 2025-04-04 23:46:35 | MASTER-OAFA | (08h 07m 46.04s , +34d 59m 09.7s) | C | 40 | 16.5 | 34039 | 2025-04-04 23:46:35 | MASTER-OAFA | (08h 18m 48.79s , +35d 21m 37.5s) | C | 60 | 18.6 | 34105 | 2025-04-04 23:47:51 | MASTER-OAFA | (08h 07m 44.23s , +35d 00m 11.7s) | C | 40 | 16.6 | 34116 | 2025-04-04 23:47:51 | MASTER-OAFA | (08h 18m 47.13s , +35d 22m 39.2s) | C | 60 | 18.6 | 34183 | 2025-04-04 23:49:09 | MASTER-OAFA | (08h 07m 50.81s , +34d 59m 13.6s) | C | 40 | 16.6 | 34193 | 2025-04-04 23:49:09 | MASTER-OAFA | (08h 18m 53.60s , +35d 21m 41.4s) | C | 60 | 18.6 | 34258 | 2025-04-04 23:50:24 | MASTER-OAFA | (08h 07m 43.46s , +34d 58m 15.9s) | C | 40 | 16.7 | 34268 | 2025-04-04 23:50:24 | MASTER-OAFA | (08h 18m 46.23s , +35d 20m 43.3s) | C | 60 | 18.9 | 34334 | 2025-04-04 23:51:40 | MASTER-OAFA | (08h 07m 49.53s , +34d 58m 37.1s) | C | 40 | 16.7 | 34344 | 2025-04-04 23:51:40 | MASTER-OAFA | (08h 18m 52.40s , +35d 21m 04.5s) | C | 60 | 19.0 | 34412 | 2025-04-04 23:52:58 | MASTER-OAFA | (08h 07m 45.63s , +34d 59m 52.0s) | C | 40 | 16.7 | 34422 | 2025-04-04 23:52:58 | MASTER-OAFA | (08h 18m 48.68s , +35d 22m 19.3s) | C | 60 | 19.0 | 34490 | 2025-04-04 23:54:16 | MASTER-OAFA | (08h 07m 45.61s , +34d 58m 24.1s) | C | 40 | 16.7 | 34500 | 2025-04-04 23:54:16 | MASTER-OAFA | (08h 18m 48.48s , +35d 20m 51.3s) | C | 60 | 19.0 | 34568 | 2025-04-04 23:55:34 | MASTER-OAFA | (08h 07m 47.51s , +34d 59m 56.5s) | C | 40 | 16.7 | 34578 | 2025-04-04 23:55:34 | MASTER-OAFA | (08h 18m 50.62s , +35d 22m 23.7s) | C | 60 | 19.0 | 34694 | 2025-04-04 23:57:00 | MASTER-OAFA | (08h 18m 44.27s , +35d 21m 54.2s) | C | 120 | 19.3 | 34823 | 2025-04-04 23:59:19 | MASTER-OAFA | (08h 07m 41.05s , +35d 00m 30.6s) | C | 100 | 16.9 | 34833 | 2025-04-04 23:59:19 | MASTER-OAFA | (08h 18m 44.29s , +35d 22m 57.6s) | C | 120 | 19.3 | 34970 | 2025-04-05 00:01:46 | MASTER-OAFA | (08h 07m 46.89s , +34d 59m 33.9s) | C | 100 | 17.1 | 34981 | 2025-04-05 00:01:46 | MASTER-OAFA | (08h 18m 50.01s , +35d 22m 01.1s) | C | 120 | 19.3 | 35095 | 2025-04-05 00:04:06 | MASTER-OAFA | (08h 07m 41.46s , +34d 58m 36.8s) | C | 70 | 16.9 | 35105 | 2025-04-05 00:04:06 | MASTER-OAFA | (08h 18m 44.44s , +35d 21m 04.0s) | C | 90 | 19.1 | 35202 | 2025-04-05 00:05:53 | MASTER-OAFA | (08h 07m 45.68s , +34d 58m 59.5s) | C | 70 | 17.0 | 35212 | 2025-04-05 00:05:53 | MASTER-OAFA | (08h 18m 48.74s , +35d 21m 26.6s) | C | 90 | 19.1 | 35308 | 2025-04-05 00:07:39 | MASTER-OAFA | (08h 07m 42.99s , +35d 00m 18.1s) | C | 70 | 16.9 | 35319 | 2025-04-05 00:07:39 | MASTER-OAFA | (08h 18m 46.22s , +35d 22m 44.9s) | C | 90 | 19.1 | 35398 | 2025-04-05 00:09:24 | MASTER-OAFA | (08h 07m 42.93s , +34d 59m 00.1s) | C | 40 | 16.7 | Filter C is a clear (unfiltred) band.

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

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