TITLE: GCN CIRCULAR NUMBER: 22801 SUBJECT: GRB 180620A: MASTER OT observation DATE: 18/06/20 09:27:40 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs N.Tyurina, V. Lipunov, E. Gorbovskoy, V.Kornilov, A.Kuznetsov, I. Gorbunov, D. Vlasenko, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, C. Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) D. Buckley South African Astronomical Observatory O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk MASTER-OAFA robotic telescope (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), was pointed to the Swift GRB180620A ( Evans et al. GCN #22798) 20 sec after Notice and 41 sec after trigger time at 2018-06-20 08:35:39 UT. We see OT at Swift UVOT coordinates ~17 mag (Evans et al. GCN #22798). ==================================================================== The observations made on zenit distance = 72 degrees, galaxy latitude b = 12 degree. The moon (49 % bright part) below the horizon (The altitude of the Moon is -50 degree ). The sun altitude is -37.3 degree. The object can be observed till 2018-06-20 10:23:39.