TITLE: GCN CIRCULAR NUMBER: 25527 SUBJECT: Integral GRB190828.78 Global MASTER-Net observations report DATE: 19/08/28 19:39:17 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) was pointed to the Integral GRB190828.78 (trigger No 8364,16h 48m 51.120s , -24d 35m 06.00s, R=0.0516667) errorbox 20 sec after notice time and 31 sec after trigger time at 2019-08-28 18:49:11 UT, with upper limit up to 19.2 mag. The observations began at zenit distance = 25 deg. The sun altitude is -32.4 deg. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Integral GRB190828.78 errorbox 30 sec after notice time and 41 sec after trigger time at 2019-08-28 18:49:21 UT, with upper limit up to 16.3 mag. The observations began at zenit distance = 78 deg. The sun altitude is -23.3 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=1118498 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 37 | MASTER-SAAO | P\ | 10 | 17.2 | 52 | MASTER-SAAO | P\ | 40 | 18.0 | Coadd 46 | MASTER-Tavrida | C | 10 | 15.9 | 61 | MASTER-Tavrida | C | 40 | 16.3 | Coadd 63 | MASTER-SAAO | P\ | 10 | 17.1 | 80 | MASTER-Tavrida | C | 10 | 15.6 | 93 | MASTER-SAAO | P\ | 20 | 17.7 | 119 | MASTER-Tavrida | C | 20 | 16.0 | 130 | MASTER-SAAO | P\ | 20 | 17.8 | 165 | MASTER-SAAO | P\ | 90 | 18.6 | Coadd 171 | MASTER-SAAO | P\ | 30 | 18.0 | 222 | MASTER-SAAO | P\ | 40 | 18.3 | 283 | MASTER-SAAO | P\ | 50 | 18.4 | 353 | MASTER-SAAO | P\ | 190 | 19.1 | Coadd 354 | MASTER-SAAO | P\ | 60 | 18.6 | 680 | MASTER-SAAO | P\ | 370 | 19.2 | Coadd Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.