TITLE: GCN CIRCULAR NUMBER: 25849 SUBJECT: Swift GRB190926.41: Global MASTER-Net observations report DATE: 19/09/26 10:46:35 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) was pointed to the Swift GRB190926.41 (trigger No 926515,06h 42m 23.760s , +59d 30m 39.60s, R=0.05) errorbox 1124 sec after notice time and 1233 sec after trigger time at 2019-09-26 10:12:49 UT, with upper limit up to 18.0 mag. Observations started at twilight. The observations began at zenit distance = 71 deg. The sun altitude is -8.9 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=1150077 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 1263 | MASTER-Amur | P/ | 60 | 13.9 | 1607 | MASTER-Amur | P/ | 60 | 14.1 | 2561 | MASTER-Amur | C | 180 | 17.9 | 2770 | MASTER-Amur | C | 180 | 18.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.