TITLE: GCN CIRCULAR NUMBER: 28334 SUBJECT: Swift GRB200901.16: Global MASTER-Net observations report DATE: 20/09/01 03:54:13 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-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) was pointed to the Swift GRB200901.16 (trigger No 994143,04h 07m 01.92s , -59d 52m 48.0s, R=0.05) errorbox 25 sec after notice time and 46 sec after trigger time at 2020-09-01 03:48:18 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 65 deg. The sun altitude is -64.8 deg. The galactic latitude b = -43 deg., longitude l = 271 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1431471 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 52 | MASTER-OAFA | C | 10 | 16.4 | 81 | MASTER-OAFA | C | 10 | 16.5 | 116 | MASTER-OAFA | C | 20 | 16.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.