TITLE: GCN CIRCULAR NUMBER: 40099 SUBJECT: IceCube Alert 250406.95: Global MASTER-Net observations report DATE: 25/04/06 23:39:44 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-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) was pointed to the IceCube Alert 250406.95 (trigger No 31006975,05h 27m 14.40s , +16d 40m 08.4s, R=0.51) errorbox 1665 sec after notice time and 1717 sec after trigger time at 2025-04-06 23:19:12 UT, with upper limit up to 19.3 mag. Observations started at twilight. The observations began at zenith distance = 57 deg. The sun altitude is -12.5 deg. The galactic latitude b = -9 deg., longitude l = 189 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2835304 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1798 | 2025-04-06 23:19:12 | MASTER-OAFA | (05h 36m 30.18s , +17d 17m 13.8s) | C | 160 | 15.5 | 1984 | 2025-04-06 23:22:18 | MASTER-OAFA | (05h 36m 29.96s , +17d 17m 16.2s) | C | 160 | 16.3 | 2144 | 2025-04-06 23:22:18 | MASTER-OAFA | (05h 36m 29.96s , +17d 17m 16.2s) | C | 480 | 16.9 | Coadd 2170 | 2025-04-06 23:25:24 | MASTER-OAFA | (05h 36m 29.72s , +17d 17m 19.0s) | C | 160 | 16.5 | 2180 | 2025-04-06 23:25:25 | MASTER-OAFA | (05h 27m 00.20s , +16d 54m 03.9s) | C | 180 | 15.6 | 2356 | 2025-04-06 23:28:31 | MASTER-OAFA | (05h 36m 29.47s , +17d 17m 21.0s) | C | 160 | 16.8 | 2366 | 2025-04-06 23:28:31 | MASTER-OAFA | (05h 27m 00.08s , +16d 54m 05.7s) | C | 180 | 19.1 | 2542 | 2025-04-06 23:31:37 | MASTER-OAFA | (05h 36m 29.25s , +17d 17m 22.1s) | C | 160 | 16.6 | 2552 | 2025-04-06 23:31:37 | MASTER-OAFA | (05h 26m 59.99s , +16d 54m 07.1s) | C | 180 | 19.3 | 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/40099. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...