TITLE: GCN CIRCULAR NUMBER: 24428 SUBJECT: Fermi GRB190508.81 Global MASTER-Net observations report DATE: 19/05/08 20:01:24 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB190508.81 (trigger No 579036175, 11h 51m 50.40s , +23d 31m 48.00s, R=2.12) errorbox 151 sec after trigger time at 2019-05-08 19:25:21 UT, with upper limit up to 17.2 mag. The observations began at zenit distance = 56 deg. The sun altitude is -44.7 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB190508.81 errorbox 583 sec after trigger time at 2019-05-08 19:32:34 UT, with upper limit up to 19.1 mag. The observations began at zenit distance = 27 deg. The sun altitude is -26.1 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/observ.php?id=1012657 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 166 | 2019-05-08 19:25:21 | MASTER-SAAO | ( 11h 50m 45.97s , +26d 6m 18.86s) | C | 30 | 14.3 | 216 | 2019-05-08 19:25:21 | MASTER-SAAO | ( 11h 50m 45.96s , +26d 6m 18.88s) | C | 130 | 15.6 | Coadd 231 | 2019-05-08 19:26:21 | MASTER-SAAO | ( 11h 50m 45.90s , +26d 6m 18.87s) | C | 40 | 14.9 | 311 | 2019-05-08 19:27:31 | MASTER-SAAO | ( 11h 50m 45.83s , +26d 6m 18.98s) | C | 60 | 15.3 | 407 | 2019-05-08 19:29:01 | MASTER-SAAO | ( 11h 50m 45.76s , +26d 6m 18.67s) | C | 70 | 17.3 | 644 | 2019-05-08 19:32:34 | MASTER-Kislovodsk | ( 11h 56m 28.05s , +23d 33m 45.38s) | C | 120 | 18.8 | 644 | 2019-05-08 19:32:34 | MASTER-Kislovodsk | ( 11h 47m 19.94s , +24d 0m 20.14s) | C | 120 | 18.5 | 803 | 2019-05-08 19:34:58 | MASTER-Kislovodsk | ( 11h 56m 27.92s , +23d 33m 38.82s) | C | 150 | 19.1 | 803 | 2019-05-08 19:34:58 | MASTER-Kislovodsk | ( 11h 47m 19.98s , +24d 0m 11.85s) | C | 150 | 19.0 | 1355 | 2019-05-08 19:44:55 | MASTER-Kislovodsk | ( 12h 2m 44.46s , +24d 2m 04.36s) | C | 60 | 18.9 | 1460 | 2019-05-08 19:46:40 | MASTER-Kislovodsk | ( 11h 52m 05.96s , +22d 1m 55.45s) | C | 60 | 18.3 | 1460 | 2019-05-08 19:46:40 | MASTER-Kislovodsk | ( 11h 43m 05.32s , +22d 28m 15.35s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.