TITLE: GCN CIRCULAR NUMBER: 13443 SUBJECT: GRB 120711A: MASTER early OT detection DATE: 12/07/11 15:51:48 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs H. Levato and C. Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) C. Mallamaci, C. Lopez and F. Podest Observatorio Astronomico Felix Aguilar (OAFA) D. Denisenko, A. Kuznetsov, V. Lipunov, E. Gorbovskoy, V. Kornilov, D. Kuvshinov, A. Belinski, N. Tyurina, N. Shatskiy, P. Balanutsa, D. Zimnukhov, V.V. Chazov Lomonosov Moscow State University, Sternberg Astronomical Institute A. Tlatov, A.V. Parhomenko, D. Dormidontov, V. Sennik Kislovodsk Solar Station of the Pulkovo Observatory K. Ivanov, S. Yazev, N.M. Budnev, O. Gres, O. Chuvalaev, V.A. Poleshchuk Irkutsk State University V. Yurkov, Yu. Sergienko, D. Varda, E. Sinyakov Blagoveschensk Educational State University, Blagoveschensk V. Krushinski, I. Zalozhnich, A. Popov, A. Bourdanov, A. Punanova Ural Federal University MASTER-ICATE robotic very wide field cameras (FOV=2x384 square degrees, D=72mm, f/1.2, 1 pix = 22 arcsec, http://observ.pereplet.ru) located in Argentina (Observatorio Astronomico Felix Aguilar, http://93.180.27.230:8080/) were pointed to the INTEGRAL TRIGGER_NUM 6599 = Fermi TRIGGER_NUM: 363667496 60 sec after INTEGRAL trigger Time (Gotz et al., GCN 13434, Gruber and Pelassa, GCN 13437) on 2012-07-11 at 02:45:54.107 UT. Our cameras are continuously imaging the sky with 5 sec exposures. On our first unfiltered image (5 sec exposure) we have not found any OT. We see OT (Lacluyze et al., GCN 13430, Zheng et al., GCN 13432, Elliot et al., GCN 13438, Fugazza et al., GCN 13439 and Tanvir et al., GCN 13441) on the sum of 4 images obtained between T0+121s and T0+141s with the unfiltered magnitude 12.5. Nothing is visible at the OT position on the individual (m_lim = 12.0) and combined (m_lim=13.0) images obtained before T0+121s and after T0+141s. This message can be cited.