TITLE: GCN CIRCULAR NUMBER: 25637 SUBJECT: Fermi trigger No 589223981 Global MASTER-Net observations report DATE: 19/09/03 23:31:53 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 (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 GRB190903.72 (trigger No 589223981,04h 09m 43.200s , -64d 51m 36.00s, R=6.3) errorbox 20807 sec after trigger time at 2019-09-03 23:06:23 UT, with upper limit up to 19.9 mag. The observations began at zenit distance = 56 deg. The sun altitude is -64.6 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1124611 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 20897 | 2019-09-03 23:06:23 | MASTER-SAAO | (04h 24m 50.365s , -62d 00m 53.04s) | C | 180 | 19.4 | 21347 | 2019-09-03 23:13:52 | MASTER-SAAO | (04h 08m 40.297s , -60d 01m 21.22s) | C | 180 | 19.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.