TITLE: GCN CIRCULAR NUMBER: 17456 SUBJECT: GRB 150212A: MASTER optical observations DATE: 15/02/12 13:22:42 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, A.Sankovich Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to the GRB150212A (Page et. al. GCN 17449) 32 sec after notice time and 47 sec after trigger time at 2015-02-12 10:58:06 UT in two polarization. Unfortunately we were unable to obtain satisfactory data on the first images due to clouds and high zenith distance (z~75 d). In the process of further observations we do not see the optical transient and obtained the following upper limits: T_start T-Tmid Expt. Mlimit 11:08:50 761 140 11.5 11:11:52 958 170 11.5 11:15:26 1177 180 12.5 11:26:34 1845 180 12.6 11:32:12 2183 180 15.0 11:32:12 3447 1800 16.7 11:35:58 2641 540 16.1 So weak upper limits associated with the observation through clouds and large zenith distance of the object.