TITLE: GCN CIRCULAR NUMBER: 24426 SUBJECT: Fermi GRB190507.71 Global MASTER-Net observations report DATE: 19/05/08 19:16:47 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko (Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University) A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory) K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk (Irkutsk State University) V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University, Blagoveschensk) R. Podesta, Carlos Lopez and F. Podesta (Observatorio Astronomico Felix Aguilar (OAFA)) Hugo Levato and Carlos Saffe (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias) D. Buckley, S. Potter, A. Kniazev, M. Kotze (South African Astronomical Observatory) 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 GRB190507.71 (trigger No 578941521, 5h 44m 52.80s , -61d 52m 48.00s, R=15.03) errorbox 1 days 2581 sec after notice time and 1 days 2623 sec after trigger time at 2019-05-08 17:48:59 UT, with upper limit up to 15.5 mag. The observations began at zenit distance = 52 deg. The sun altitude is -24.3 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=1011480 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 89053 | 2019-05-08 17:48:59 | MASTER-SAAO | ( 4h 20m 34.05s , -54d 59m 39.67s) | C | 60 | 15.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.