TITLE: GCN CIRCULAR NUMBER: 27252 SUBJECT: Fermi trigger No 604565918: Global MASTER-Net observations report DATE: 20/02/28 09:30:36 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-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) started inspect of the Fermi GRB200228.29 (trigger No 604565918,21h 52m 02.40s , -46d 27m 00.0s, R=1.51) errorbox 5750 sec after trigger time at 2020-02-28 08:34:23 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 81 deg. The sun altitude is -23.1 deg. The galactic latitude b = -51 deg., longitude l = 352 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1300070 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 5840 | 2020-02-28 08:34:23 | MASTER-OAFA | (21h 50m 46.37s , -46d 04m 53.9s) | C | 180 | 17.4 | 6054 | 2020-02-28 08:37:58 | MASTER-OAFA | (21h 50m 58.67s , -46d 06m 26.5s) | C | 180 | 18.1 | 7542 | 2020-02-28 09:02:45 | MASTER-OAFA | (21h 47m 01.75s , -47d 53m 08.8s) | C | 180 | 18.5 | 7753 | 2020-02-28 09:06:16 | MASTER-OAFA | (21h 46m 54.08s , -47d 53m 30.7s) | C | 180 | 18.9 | 7964 | 2020-02-28 09:09:48 | MASTER-OAFA | (21h 58m 56.72s , -46d 34m 38.3s) | C | 180 | 18.6 | 8175 | 2020-02-28 09:13:19 | MASTER-OAFA | (21h 59m 03.86s , -46d 35m 37.3s) | C | 180 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.