TITLE: GCN CIRCULAR NUMBER: 42303 SUBJECT: IceCube Alert 251014.77: Global MASTER-Net observations report DATE: 25/10/15 22:39:32 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs 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) was pointed to the IceCube Alert 251014.77 (trigger No 75492250,00h 11m 35.28s , +02d 54m 43.2s, R=0.51) errorbox 1 days 12049 sec after notice time and 1 days 12105 sec after trigger time at 2025-10-15 21:54:57 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 36 deg. The sun altitude is -48.7 deg. The galactic latitude b = -58 deg., longitude l = 105 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3014752 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 98536 | 2025-10-15 21:54:57 | MASTER-SAAO | (00h 08m 40.80s , +02d 48m 16.0s) | C | 60 | 19.4 | 98536 | 2025-10-15 21:54:57 | MASTER-SAAO | (00h 10m 29.80s , +02d 32m 25.7s) | C | 60 | 19.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.