TITLE: GCN CIRCULAR NUMBER: 22503 SUBJECT: GRB180316A: MASTER-IAC OT light curve DATE: 18/03/16 07:15:51 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, N.Tyurina, V.Kornilov, E.Gorbovskoy, P.Balanutsa, V.Vladimirov, A.Krylov, I.Gorbunov, A.Kuznetsov, V.Chazov, D. Kuvshinov, D.Zimnukhov (Lomonosov Moscow State University, SAI), R. Rebolo, M. Serra-Ricart (The Instituto de Astrofisica de Canarias), R.Podesta, C.Lopez, F. Podesta (Observatorio Astronomico Felix Aguilar (OAFA),National University of San Juan, Argentina), H. Levato, C. Saffe (Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina), D.Buckley, S. Potter (South African Astronomical Observatory), O.Gres, N.M.Budnev (Irkutsk State University), A. Tlatov, V.Senik, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory) V.Yurkov, A.Gabovich, Yu.Sergienko (Blagoveschensk Educational State University, Blagoveschensk), MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB180316A (Melandri et al GCN22500) 15 sec after notice time and 44 sec after trigger time at 2018-03-16 04:58:09 UT . There is OT(GCN 22502) as the GRB counterpart coordinates (17h 41m 42s.82, + 00d 44m 53s.6 ) error =+-0.5" The automatical OT light curve available at http://master.sai.msu.ru/static/OT/LC_GRB180316A.png The message may be cited. ==================================================================== The observations made on zenit distance = 42 degrees, galaxy latitude b = 15 degree. The moon ( 2 % bright part) below the horizon (The altitude of the Moon is -22 degree ). The sun altitude is -30.4 degree. The object can be observed till sunrise at 2018-03-16 07:14:55