TITLE: GCN CIRCULAR NUMBER: 39950 SUBJECT: Fermi GRB 250330A: Global MASTER-Net observations report DATE: 25/03/30 19:16:02 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250330A ( Fermi GBM team, GCN 39944) errorbox 41642 sec after notice time and 41678 sec after trigger time at 2025-03-30 17:42:16 UT, with upper limit up to 18.5 mag. Observations started at twilight. The observations began at zenith distance = 69 deg. The sun altitude is -14.6 deg. The galactic latitude b = -16 deg., longitude l = 316 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2828018 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 41709 | 2025-03-30 17:42:16 | MASTER-SAAO | (16h 01m 09.95s , -72d 45m 24.7s) | C | 60 | 18.1 | 41788 | 2025-03-30 17:43:36 | MASTER-SAAO | (16h 28m 26.03s , -72d 45m 15.7s) | C | 60 | 18.2 | 41868 | 2025-03-30 17:44:56 | MASTER-SAAO | (16h 02m 18.38s , -74d 39m 19.9s) | C | 60 | 18.0 | 41947 | 2025-03-30 17:46:15 | MASTER-SAAO | (16h 32m 49.13s , -74d 37m 47.3s) | C | 60 | 18.3 | 42026 | 2025-03-30 17:47:34 | MASTER-SAAO | (15h 04m 24.83s , -74d 37m 14.9s) | C | 60 | 18.4 | 42106 | 2025-03-30 17:48:54 | MASTER-SAAO | (15h 34m 57.62s , -74d 38m 25.7s) | C | 60 | 18.4 | 42186 | 2025-03-30 17:50:14 | MASTER-SAAO | (15h 09m 38.19s , -72d 45m 00.7s) | C | 60 | 18.2 | 42265 | 2025-03-30 17:51:33 | MASTER-SAAO | (15h 36m 45.01s , -72d 44m 01.7s) | C | 60 | 18.3 | 42345 | 2025-03-30 17:52:52 | MASTER-SAAO | (16h 01m 11.29s , -72d 45m 24.8s) | C | 60 | 18.2 | 42424 | 2025-03-30 17:54:12 | MASTER-SAAO | (16h 28m 23.83s , -72d 44m 12.1s) | C | 60 | 18.2 | 42866 | 2025-03-30 18:01:34 | MASTER-SAAO | (16h 02m 13.55s , -74d 39m 54.2s) | C | 60 | 17.9 | 42945 | 2025-03-30 18:02:53 | MASTER-SAAO | (16h 32m 48.33s , -74d 40m 05.2s) | C | 60 | 18.3 | 43025 | 2025-03-30 18:04:13 | MASTER-SAAO | (15h 04m 23.51s , -74d 37m 45.9s) | C | 60 | 18.4 | 43104 | 2025-03-30 18:05:32 | MASTER-SAAO | (15h 34m 50.67s , -74d 39m 22.5s) | C | 60 | 18.5 | 43184 | 2025-03-30 18:06:52 | MASTER-SAAO | (15h 09m 34.64s , -72d 44m 00.2s) | C | 60 | 18.2 | 43263 | 2025-03-30 18:08:11 | MASTER-SAAO | (15h 36m 38.09s , -72d 44m 59.8s) | C | 60 | 18.3 | 43343 | 2025-03-30 18:09:31 | MASTER-SAAO | (16h 01m 06.13s , -72d 44m 09.8s) | C | 60 | 18.2 | 45719 | 2025-03-30 18:49:07 | MASTER-SAAO | (16h 28m 13.93s , -72d 47m 17.6s) | C | 60 | 18.2 | 45798 | 2025-03-30 18:50:26 | MASTER-SAAO | (16h 02m 10.31s , -74d 39m 28.3s) | C | 60 | 18.1 | 45878 | 2025-03-30 18:51:46 | MASTER-SAAO | (16h 32m 34.04s , -74d 40m 31.3s) | C | 60 | 18.3 | 46778 | 2025-03-30 19:06:46 | MASTER-SAAO | (15h 04m 04.80s , -74d 39m 00.1s) | C | 60 | 18.5 | 46858 | 2025-03-30 19:08:05 | MASTER-SAAO | (15h 34m 34.17s , -74d 41m 15.3s) | C | 60 | 18.4 | 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/39950. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...