TITLE: GCN CIRCULAR NUMBER: 25810 SUBJECT: Fermi trigger No 590899086: Global MASTER-Net observations report DATE: 19/09/23 13:32:00 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-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB190923.11 (trigger No 590899086,23h 12m 40.008s , +57d 07m 00.12s, R=14) errorbox 35611 sec after trigger time at 2019-09-23 12:31:32 UT, with upper limit up to 18.7 mag. The observations began at zenit distance = 29 deg. The sun altitude is -28.0 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=1145639 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 35702 | 2019-09-23 12:31:32 | MASTER-Amur | (23h 53m 09.209s , +43d 43m 51.56s) | C | 180 | 18.6 | 35926 | 2019-09-23 12:35:17 | MASTER-Amur | (23h 53m 01.266s , +45d 43m 57.88s) | C | 180 | 18.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.