TITLE: GCN CIRCULAR NUMBER: 28795 SUBJECT: Baksan Neutrino Observatory Alert 201027.41: Global MASTER-Net observations report DATE: 20/10/27 19:21:16 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-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 Baksan Neutrino Observatory Alert 201027.41 (trigger No 1654508715,21h 50m 48.00s , -28d 54m 00.0s, R=3) errorbox 28531 sec after notice time and 29731 sec after trigger time at 2020-10-27 18:00:46 UT, with upper limit up to 18.1 mag. Observations started at twilight. The observations began at zenith distance = 1 deg. The sun altitude is -12.9 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) started inspect of the Baksan Neutrino Observatory Alert 201027.41 errorbox 32890 sec after notice time and 34091 sec after trigger time at 2020-10-27 19:13:25 UT, with upper limit up to 16.1 mag. Observations started at twilight. The observations began at zenith distance = 62 deg. The sun altitude is -11.9 deg. The galactic latitude b = -51 deg., longitude l = 20 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1470084 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 29762 | 2020-10-27 18:00:46 | MASTER-SAAO | (21h 40m 26.15s , -32d 03m 16.9s) | C | 60 | 13.9 | 29762 | 2020-10-27 18:00:46 | MASTER-SAAO | (21h 39m 26.19s , -32d 04m 00.1s) | C | 60 | 13.9 | 29863 | 2020-10-27 18:02:27 | MASTER-SAAO | (21h 31m 54.36s , -30d 04m 07.8s) | C | 60 | 18.0 | 29863 | 2020-10-27 18:02:27 | MASTER-SAAO | (21h 30m 55.70s , -30d 04m 56.7s) | C | 60 | 18.1 | 30117 | 2020-10-27 18:06:41 | MASTER-SAAO | (21h 40m 26.27s , -32d 03m 21.2s) | C | 60 | 17.0 | 30117 | 2020-10-27 18:06:41 | MASTER-SAAO | (21h 39m 26.18s , -32d 04m 06.6s) | C | 60 | 17.0 | 30197 | 2020-10-27 18:08:01 | MASTER-SAAO | (21h 31m 50.60s , -30d 05m 09.2s) | C | 60 | 17.9 | 30197 | 2020-10-27 18:08:01 | MASTER-SAAO | (21h 30m 51.78s , -30d 05m 58.6s) | C | 60 | 17.9 | 34121 | 2020-10-27 19:13:25 | MASTER-IAC | (21h 36m 06.20s , -32d 04m 37.7s) | C | 60 | 16.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.