TITLE: GCN CIRCULAR NUMBER: 28186 SUBJECT: Swift GRB200801.84: Global MASTER-Net observations report DATE: 20/08/01 20:18:40 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), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), 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-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) was pointed to the Swift GRB200801.84 (trigger No 985320,18h 46m 31.20s , -02d 59m 24.0s, R=0.05) errorbox 17 sec after notice time and 35 sec after trigger time at 2020-08-01 20:12:22 UT, with upper limit up to 15.8 mag. The observations began at zenith distance = 30 deg. The sun altitude is -52.8 deg. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB200801.84 errorbox 22 sec after notice time and 40 sec after trigger time at 2020-08-01 20:12:27 UT, with upper limit up to 15.9 mag. The observations began at zenith distance = 47 deg. The sun altitude is -24.3 deg. The galactic latitude b = -1 deg., longitude l = 30 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1412204 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 40 | MASTER-SAAO | P/ | 10 | 15.7 | 40 | MASTER-SAAO | P\ | 10 | 15.8 | 45 | MASTER-Tavrida | C | 10 | 15.9 | 76 | MASTER-Tavrida | C | 10 | 15.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.