TITLE: GCN CIRCULAR NUMBER: 25114 SUBJECT: LIGO/Virgo S190720a Global MASTER-Net observations report DATE: 19/07/20 02:45:17 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-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 S190720a errorbox 1846 sec after notice time and 2062 sec after trigger time at 2019-07-20 00:42:58 UT, with upper limit up to 16.4 mag. The observations began at zenit distance = 78 deg. The sun altitude is -36.1 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=10525 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 2152 | 2019-07-20 00:42:58 | MASTER-OAFA | ( 1h 8m 45.30s , -66d 6m 16.82s) | C | 180 | 16.4 | 2682 | 2019-07-20 00:51:47 | MASTER-OAFA | ( 1h 3m 44.19s , -64d 6m 37.00s) | C | 180 | 16.0 | 3167 | 2019-07-20 00:59:52 | MASTER-OAFA | ( 1h 22m 04.77s , -64d 6m 07.17s) | C | 180 | 15.9 | 3653 | 2019-07-20 01:07:58 | MASTER-OAFA | ( 0h 55m 50.61s , -60d 6m 41.48s) | C | 180 | 15.1 | 4137 | 2019-07-20 01:16:02 | MASTER-OAFA | ( 1h 22m 03.76s , -64d 6m 04.84s) | C | 180 | 15.8 | 4675 | 2019-07-20 01:25:01 | MASTER-OAFA | ( 1h 11m 53.80s , -60d 6m 31.76s) | C | 180 | 15.0 | 5160 | 2019-07-20 01:33:05 | MASTER-OAFA | ( 0h 21m 11.67s , -56d 7m 01.30s) | C | 180 | 15.2 | 5657 | 2019-07-20 01:41:22 | MASTER-OAFA | ( 0h 20m 09.20s , -54d 6m 41.58s) | C | 180 | 15.0 | 8034 | 2019-07-20 02:20:59 | MASTER-OAFA | ( 0h 33m 48.98s , -54d 6m 47.83s) | C | 180 | 14.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.