TITLE: GCN CIRCULAR NUMBER: 24637 SUBJECT: LIGO/Virgo S190521r Global MASTER-Net observations report DATE: 19/05/21 11:01:53 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-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 S190521r errorbox 427 sec after trigger time at 2019-05-21 07:51:06 UT, with upper limit up to 17.6 mag. The observations began at zenit distance = 75 deg. The sun altitude is -44.1 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=10407 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 473 | 2019-05-21 07:51:06 | MASTER-OAFA | ( 20h 34m 44.39s , +32d 44m 02.74s) | C | 90 | 17.0 | 598 | 2019-05-21 07:51:06 | MASTER-OAFA | ( 20h 34m 44.40s , +32d 44m 02.69s) | C | 340 | 17.6 | Coadd 613 | 2019-05-21 07:53:17 | MASTER-OAFA | ( 20h 34m 44.20s , +32d 44m 08.83s) | C | 110 | 17.1 | 781 | 2019-05-21 07:55:49 | MASTER-OAFA | ( 20h 34m 44.01s , +32d 44m 13.71s) | C | 140 | 17.1 | 982 | 2019-05-21 07:58:51 | MASTER-OAFA | ( 20h 34m 43.80s , +32d 44m 16.83s) | C | 180 | 17.2 | 1904 | 2019-05-21 08:14:12 | MASTER-OAFA | ( 21h 7m 57.50s , +33d 55m 58.59s) | C | 180 | 16.6 | 2603 | 2019-05-21 08:25:52 | MASTER-OAFA | ( 21h 7m 57.26s , +33d 55m 38.68s) | C | 180 | 16.6 | 2835 | 2019-05-21 08:29:43 | MASTER-OAFA | ( 21h 17m 35.60s , +33d 55m 57.36s) | C | 180 | 16.9 | 3015 | 2019-05-21 08:29:43 | MASTER-OAFA | ( 21h 17m 35.60s , +33d 55m 57.34s) | C | 540 | 17.4 | Coadd 3059 | 2019-05-21 08:33:27 | MASTER-OAFA | ( 21h 17m 33.96s , +33d 56m 01.41s) | C | 180 | 16.9 | 3330 | 2019-05-21 08:37:59 | MASTER-OAFA | ( 20h 39m 28.03s , +31d 56m 43.84s) | C | 180 | 17.1 | 3557 | 2019-05-21 08:41:45 | MASTER-OAFA | ( 21h 17m 33.53s , +33d 55m 47.16s) | C | 180 | 17.0 | 3784 | 2019-05-21 08:45:33 | MASTER-OAFA | ( 21h 46m 31.06s , +33d 55m 41.51s) | C | 180 | 17.1 | 4094 | 2019-05-21 08:50:43 | MASTER-OAFA | ( 20h 39m 29.03s , +31d 56m 24.26s) | C | 180 | 17.2 | 4457 | 2019-05-21 08:56:46 | MASTER-OAFA | ( 20h 34m 42.15s , +32d 44m 17.24s) | C | 180 | 17.1 | 4637 | 2019-05-21 08:56:46 | MASTER-OAFA | ( 20h 34m 42.15s , +32d 44m 17.14s) | C | 540 | 17.5 | Coadd 4679 | 2019-05-21 09:00:27 | MASTER-OAFA | ( 20h 34m 41.96s , +32d 44m 16.49s) | C | 180 | 17.2 | 4900 | 2019-05-21 09:04:09 | MASTER-OAFA | ( 20h 34m 41.81s , +32d 44m 14.63s) | C | 180 | 17.2 | 5121 | 2019-05-21 09:07:50 | MASTER-OAFA | ( 20h 34m 41.74s , +32d 44m 14.01s) | C | 180 | 17.2 | 5348 | 2019-05-21 09:11:36 | MASTER-OAFA | ( 21h 46m 28.55s , +33d 55m 37.61s) | C | 180 | 17.1 | 5577 | 2019-05-21 09:15:25 | MASTER-OAFA | ( 21h 56m 07.73s , +33d 55m 09.20s) | C | 180 | 17.1 | 6036 | 2019-05-21 09:23:05 | MASTER-OAFA | ( 20h 48m 54.49s , +31d 56m 28.30s) | C | 180 | 16.9 | 6268 | 2019-05-21 09:26:56 | MASTER-OAFA | ( 21h 56m 07.41s , +33d 55m 27.03s) | C | 180 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.