TITLE: GCN CIRCULAR NUMBER: 25759 SUBJECT: GRB190915A: MASTER optical observation of BALROG Fermi GRB localization DATE: 19/09/16 07:41:38 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, F.Balakin, N.Tyurina,P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov,V.Senik, T.Pogrosheva, K.Pozdnyakov, A.Chasovnikov, V.Topolev, 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 Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010,Advances in Astronomy, vol.2010, 30L) started inspect of Fermi GRB190916A (GBM team GCN 25750, Trig.N 590219102, Ttrig=05:44:57 UT on 15 Sep 2019 ) BALROG localization (Kunzweiler et al. GCN 25751, R.A.,Dec(2000)=54.2+/-4.5 , 7.2+/-3.1 ) 12 sec after notice time at MASTER-IAC, MASTER-OAFA, MASTER-SAAO. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) started inspect of the FERMI GRB 190915A BALROG localization 12 sec after notice time (1594 sec after trigger time) at 2019-09-15 06:11:31 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenit distance = 26 deg. The sun altitude is -8.8 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the FERMI GRB 190915A BALROG localization 25 sec after notice time (1607 sec after trigger time) at 2019-09-15 06:11:44 UT, with upper limit up to 17.7 mag. The observations began at zenit distance = 52 deg. The sun altitude is -53.4 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 190915A BALROG localization at 2019-09-15 21:31:37 UT, with upper limit up to 18.9 mag. The observations began at zenit distance = 77 deg. The sun altitude is -57.5 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/event.php?id=1136619 The observation and reduction will be continued. The message may be cited.