TITLE: GCN CIRCULAR NUMBER: 30470 SUBJECT: Fermi trigger No 648359752: Global MASTER-Net observations report DATE: 21/07/19 04:31:12 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, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB210719.16 (trigger No 648359752,13h 43m 55.20s , -01d 00m 36.0s, R=3.82) errorbox 453 sec after notice time and 654 sec after trigger time at 2021-07-19 04:06:41 UT, with upper limit up to 15.6 mag. The observations began at zenith distance = 86 deg. The sun altitude is -77.3 deg. The galactic latitude b = 59 deg., longitude l = 330 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1664160 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 719 | 2021-07-19 04:06:41 | MASTER-OAFA | (13h 39m 26.94s , -00d 12m 15.8s) | C | 130 | 15.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.