TITLE: GCN CIRCULAR NUMBER: 27528 SUBJECT: Baksan Neutrino Observatory Alert 200409.81: Global MASTER-Net observations report DATE: 20/04/10 17:42:12 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 200409.81 (trigger No 1637177030,03h 31m 36.00s , -23d 30m 00.0s, R=3) errorbox 77311 sec after notice time and 77994 sec after trigger time at 2020-04-10 17:03:44 UT, with upper limit up to 18.9 mag. Observations started at twilight. The observations began at zenith distance = 55 deg. The sun altitude is -9.3 deg. The galactic latitude b = -53 deg., longitude l = 216 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1333515 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 78024 | 2020-04-10 17:03:44 | MASTER-SAAO | (03h 32m 32.87s , -24d 03m 08.1s) | C | 60 | 17.6 | 78027 | 2020-04-10 17:03:46 | MASTER-SAAO | (03h 24m 57.65s , -24d 04m 38.2s) | C | 60 | 17.4 | 78104 | 2020-04-10 17:05:04 | MASTER-SAAO | (03h 29m 26.89s , -22d 04m 11.6s) | C | 60 | 18.1 | 78106 | 2020-04-10 17:05:06 | MASTER-SAAO | (03h 21m 58.45s , -22d 05m 41.3s) | C | 60 | 17.7 | 78184 | 2020-04-10 17:06:23 | MASTER-SAAO | (03h 36m 05.44s , -26d 05m 00.2s) | C | 60 | 18.2 | 78186 | 2020-04-10 17:06:25 | MASTER-SAAO | (03h 28m 22.52s , -26d 06m 29.3s) | C | 60 | 17.8 | 78263 | 2020-04-10 17:07:43 | MASTER-SAAO | (03h 46m 42.88s , -22d 04m 06.1s) | C | 60 | 18.2 | 78266 | 2020-04-10 17:07:45 | MASTER-SAAO | (03h 39m 14.24s , -22d 05m 36.1s) | C | 60 | 18.3 | 78343 | 2020-04-10 17:09:02 | MASTER-SAAO | (03h 32m 35.49s , -24d 03m 13.1s) | C | 60 | 18.3 | 78345 | 2020-04-10 17:09:05 | MASTER-SAAO | (03h 25m 00.27s , -24d 04m 41.7s) | C | 60 | 18.1 | 78423 | 2020-04-10 17:10:22 | MASTER-SAAO | (03h 29m 24.98s , -22d 04m 52.2s) | C | 60 | 18.5 | 78425 | 2020-04-10 17:10:25 | MASTER-SAAO | (03h 21m 56.43s , -22d 06m 20.4s) | C | 60 | 18.2 | 78503 | 2020-04-10 17:11:42 | MASTER-SAAO | (03h 36m 11.26s , -26d 03m 04.2s) | C | 60 | 18.5 | 78505 | 2020-04-10 17:11:45 | MASTER-SAAO | (03h 28m 28.39s , -26d 04m 31.7s) | C | 60 | 18.4 | 78582 | 2020-04-10 17:13:02 | MASTER-SAAO | (03h 46m 36.72s , -22d 03m 35.5s) | C | 60 | 18.7 | 78585 | 2020-04-10 17:13:04 | MASTER-SAAO | (03h 39m 08.01s , -22d 05m 03.9s) | C | 60 | 18.7 | 78743 | 2020-04-10 17:15:43 | MASTER-SAAO | (03h 50m 08.84s , -24d 03m 34.7s) | C | 60 | 18.5 | 78745 | 2020-04-10 17:15:45 | MASTER-SAAO | (03h 42m 33.01s , -24d 05m 03.1s) | C | 60 | 18.6 | 78903 | 2020-04-10 17:18:23 | MASTER-SAAO | (03h 40m 08.95s , -28d 04m 35.1s) | C | 60 | 18.9 | 78906 | 2020-04-10 17:18:25 | MASTER-SAAO | (03h 32m 17.17s , -28d 06m 02.6s) | C | 60 | 18.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.