TITLE: GCN CIRCULAR NUMBER: 17162 SUBJECT: GRB 141212A: MASTER early optical observations DATE: 14/12/12 15:16:48 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy,V. Lipunov, D.Denisenko, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, D.Zimnukhov, A.Kuznetsov 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 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 GRB141212A 32 sec after notice time and 46 sec after trigger time at 2014-12-12 12:14:47 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (Ukwatta et alo., GCN 17158) . The 5-sigma upper limit has been about 16.8 mag Our upper limit on first single and coadd images available on table 1: Table 1: T_start T0-T_start T0-T_mid Exptime Limit Coadd UT s s s 12:14:47.1 46 51 10 16.8 - 12:14:47.1 46 497 630 19.2 9 12:30:24.4 983 2251 2160 20.6 12 The message may be cited.