TITLE: GCN CIRCULAR NUMBER: 40811 SUBJECT: Fermi trigger No 772190032: Global MASTER-Net observations report DATE: 25/06/22 17:45:33 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-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 GRB250621.38 (trigger No 772190032,18h 06m 48.00s , -20d 49m 58.8s, R=13.3) errorbox 41094 sec after notice time and 41126 sec after trigger time at 2025-06-21 20:39:13 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 17 deg. The sun altitude is -62.0 deg. The galactic latitude b = -1 deg., longitude l = 10 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2911222 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 41157 | 2025-06-21 20:39:13 | MASTER-SAAO | (17h 03m 51.42s , -21d 48m 23.9s) | C | 60 | 18.5 | 41250 | 2025-06-21 20:40:46 | MASTER-SAAO | (17h 12m 24.87s , -21d 47m 48.3s) | C | 60 | 18.4 | 43099 | 2025-06-21 21:11:35 | MASTER-SAAO | (17h 04m 13.21s , -21d 48m 47.1s) | C | 60 | 18.5 | 43192 | 2025-06-21 21:13:08 | MASTER-SAAO | (17h 12m 43.81s , -21d 47m 46.4s) | C | 60 | 18.3 | 45253 | 2025-06-21 21:47:29 | MASTER-SAAO | (17h 04m 32.28s , -21d 47m 18.3s) | C | 60 | 18.5 | 45348 | 2025-06-21 21:49:05 | MASTER-SAAO | (17h 12m 59.51s , -21d 48m 45.5s) | C | 60 | 18.3 | 46601 | 2025-06-21 22:09:58 | MASTER-SAAO | (17h 04m 34.91s , -21d 46m 48.7s) | C | 60 | 18.5 | 46694 | 2025-06-21 22:11:31 | MASTER-SAAO | (17h 13m 09.50s , -21d 46m 18.7s) | C | 60 | 18.3 | 47940 | 2025-06-21 22:32:16 | MASTER-SAAO | (17h 04m 45.05s , -21d 47m 05.2s) | C | 60 | 18.5 | 48033 | 2025-06-21 22:33:50 | MASTER-SAAO | (17h 13m 21.76s , -21d 46m 08.2s) | C | 60 | 18.4 | 50042 | 2025-06-21 23:07:19 | MASTER-SAAO | (17h 04m 55.78s , -21d 46m 23.4s) | C | 60 | 18.6 | 50136 | 2025-06-21 23:08:52 | MASTER-SAAO | (17h 13m 27.52s , -21d 45m 19.7s) | C | 60 | 18.3 | 115062 | 2025-06-22 17:10:59 | MASTER-SAAO | (18h 11m 33.03s , -24d 48m 18.7s) | C | 60 | 17.0 | 115278 | 2025-06-22 17:14:34 | MASTER-SAAO | (18h 11m 29.34s , -24d 47m 56.5s) | C | 60 | 16.9 | 115928 | 2025-06-22 17:25:25 | MASTER-SAAO | (18h 11m 32.62s , -24d 47m 32.4s) | C | 60 | 16.8 | 116140 | 2025-06-22 17:28:57 | MASTER-SAAO | (18h 11m 32.10s , -24d 48m 31.6s) | C | 60 | 16.9 | 116348 | 2025-06-22 17:32:25 | MASTER-SAAO | (18h 11m 28.31s , -24d 48m 25.1s) | C | 60 | 16.9 | 116555 | 2025-06-22 17:35:52 | MASTER-SAAO | (18h 11m 24.50s , -24d 47m 38.3s) | C | 60 | 16.8 | 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/40811. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...