TITLE: GCN CIRCULAR NUMBER: 26332 SUBJECT: LIGO/Virgo S191204r: Global MASTER-Net observations report DATE: 19/12/04 18:16:22 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the LIGO/Virgo S191204r errorbox 401 sec after notice time and 3049 sec after trigger time at 2019-12-04 18:06:15 UT, with upper limit up to 19.2 mag. The observations began at zenith distance = 50 deg. The sun altitude is -42.5 deg. The galactic latitude b = -19 deg., longitude l = 252 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=10960 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 3139 | 2019-12-04 18:06:15 | MASTER-Tavrida | (02h 54m 34.70s , -00d 56m 20.8s) | C | 180 | 19.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.