TITLE: GCN CIRCULAR NUMBER: 42302 SUBJECT: Swift GRB251015.60: Global MASTER-Net observations report DATE: 25/10/15 22:02:26 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 Swift GRB251015.60 (trigger No 1404295,16h 20m 01.68s , -54d 51m 10.8s, R=0.05) errorbox 27211 sec after notice time and 27228 sec after trigger time at 2025-10-15 21:51:12 UT, with upper limit up to 16.1 mag. The observations began at zenith distance = 83 deg. The sun altitude is -48.5 deg. The galactic latitude b = -4 deg., longitude l = 330 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3015339 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 27319 | MASTER-SAAO | C | 180 | 15.1 | 27319 | MASTER-SAAO | C | 180 | 16.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.