TITLE: GCN CIRCULAR NUMBER: 27559 SUBJECT: Fermi GRB 200412A: Global MASTER-Net observations report DATE: 20/04/12 19:30:09 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) started inspect of the Fermi GRB 200412A ( B. Mailyan et al., GCN 27550) errorbox 36730 sec after notice time and 36757 sec after trigger time at 2020-04-12 17:09:48 UT, with upper limit up to 19.6 mag. Observations started at twilight. The observations began at zenith distance = 18 deg. The sun altitude is -11.1 deg. The galactic latitude b = 1 deg., longitude l = 261 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1334799 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 36787 | 2020-04-12 17:09:48 | MASTER-SAAO | (09h 13m 52.34s , -41d 51m 51.9s) | C | 60 | 18.4 | 37119 | 2020-04-12 17:15:21 | MASTER-SAAO | (09h 13m 54.79s , -41d 51m 51.5s) | C | 60 | 18.8 | 38182 | 2020-04-12 17:33:03 | MASTER-SAAO | (09h 10m 06.68s , -43d 53m 01.7s) | C | 60 | 19.5 | 38513 | 2020-04-12 17:38:34 | MASTER-SAAO | (09h 10m 03.48s , -43d 53m 49.3s) | C | 60 | 19.5 | 38840 | 2020-04-12 17:44:01 | MASTER-SAAO | (09h 06m 39.51s , -39d 52m 36.7s) | C | 60 | 19.5 | 38843 | 2020-04-12 17:44:04 | MASTER-SAAO | (08h 57m 23.15s , -39d 53m 40.6s) | C | 60 | 19.6 | 38922 | 2020-04-12 17:45:24 | MASTER-SAAO | (09h 02m 33.15s , -37d 54m 37.1s) | C | 60 | 19.1 | 39169 | 2020-04-12 17:49:31 | MASTER-SAAO | (09h 06m 35.97s , -39d 53m 37.7s) | C | 60 | 19.5 | 39172 | 2020-04-12 17:49:34 | MASTER-SAAO | (08h 57m 19.39s , -39d 54m 42.5s) | C | 60 | 19.6 | 39252 | 2020-04-12 17:50:54 | MASTER-SAAO | (09h 02m 39.08s , -37d 53m 08.5s) | C | 60 | 19.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.