TITLE: GCN CIRCULAR NUMBER: 24655 SUBJECT: LIGO/Virgo S190524q Global MASTER-Net observations report DATE: 19/05/24 05:17:17 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Vladimirov, D. Vlasenko, 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-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 LIGO/Virgo S190524q errorbox 164 sec after trigger time at 2019-05-24 04:54:50 UT, with upper limit up to 17.6 mag. The observations began at zenit distance = 110 deg. The sun altitude is -78.4 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/ligo_1.php?id=10440 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 254 | 2019-05-24 04:54:50 | MASTER-OAFA | ( 13h 56m 23.08s , +38d 4m 56.27s) | C | 180 | 16.4 | 483 | 2019-05-24 04:59:24 | MASTER-OAFA | ( 17h 59m 04.35s , - 4d 10m 41.43s) | C | 90 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.