TITLE: GCN CIRCULAR NUMBER: 28455 SUBJECT: Swift GRB200919.08: Global MASTER-Net observations report DATE: 20/09/19 02:02:24 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB200919.08 (trigger No 996503,11h 15m 39.84s , +32d 27m 25.2s, R=0.05) errorbox 15 sec after notice time and 83 sec after trigger time at 2020-09-19 01:53:44 UT, with upper limit up to 17.1 mag. The observations began at zenith distance = 79 deg. The sun altitude is -17.1 deg. The galactic latitude b = 69 deg., longitude l = 193 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1444350 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 93 | MASTER-Tavrida | C | 20 | 16.3 | 118 | MASTER-Tavrida | C | 70 | 16.9 | Coadd 134 | MASTER-Tavrida | C | 20 | 16.3 | 179 | MASTER-Tavrida | C | 30 | 16.3 | 235 | MASTER-Tavrida | C | 40 | 16.8 | 300 | MASTER-Tavrida | C | 50 | 16.9 | 381 | MASTER-Tavrida | C | 70 | 17.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.