TITLE: GCN CIRCULAR NUMBER: 29175 SUBJECT: Baksan Neutrino Observatory Alert 201225.54: Global MASTER-Net observations report DATE: 20/12/26 01:21:07 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, I.Gorbunov, D.Vlasenko, V.Vladimirov, A.Kuznetsov, A. Chasovnikov, V.Topolev, D.Kuvshinov, F.Balakin, V.A. Senik (Lomonosov Moscow State University, SAI, Physics Department), V.B. Petkov, M.M. Boliev, A.N. Kurenya, (Baksan Neutrino Observatory, Institute for Nuclear Research of RAS, Moscow, Russia), R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), N.M. Budnev, O. Gress, O.Ershova (Applied Physics Institute, Irkutsk State University), V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational State University), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA, San Juan National University), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE SJNU) 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) started inspect of the Baksan Neutrino Observatory Alert 201225.54 (trigger No 1659617772,05h 40m 48.00s , -47d 24m 00.0s, R=3) errorbox 43582 sec after notice time and 44112 sec after trigger time at 2020-12-26 01:11:24 UT, with upper limit up to 17.7 mag. Observations started at twilight. The observations began at zenith distance = 34 deg. The sun altitude is -16.9 deg. The galactic latitude b = -31 deg., longitude l = 254 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1511597 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 44143 | 2020-12-26 01:11:24 | MASTER-OAFA | (05h 27m 51.85s , -48d 42m 19.5s) | C | 60 | 15.0 | 44222 | 2020-12-26 01:12:44 | MASTER-OAFA | (05h 38m 46.02s , -46d 42m 52.9s) | C | 60 | 16.3 | 44302 | 2020-12-26 01:14:03 | MASTER-OAFA | (05h 41m 19.36s , -50d 42m 44.5s) | C | 60 | 17.7 | 44381 | 2020-12-26 01:15:22 | MASTER-OAFA | (05h 51m 40.66s , -48d 41m 44.5s) | C | 60 | 17.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.