TITLE: GCN CIRCULAR NUMBER: 20009 SUBJECT: GRB 161007A: MASTER-net early optical observations DATE: 16/10/07 21:45:10 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, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, A.Kuznetsov, V.V.Chazov 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.Senik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) H. Levato, C. Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to the GRB161007A 38 sec after notice time and 114 sec after trigger time at 2016-10-07 21:27:42 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box (ra=06 53 33 dec=+23 17 20 r=0.050000). The 5-sigma upper limit has been about 17.0 mag. The observations made on zenit distance = 33 degrees, galaxy latitude b = 11 degree. The moon (38 % bright part) below the horizon (The altitude of the Moon is -56 degree ). MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB161007A 33 sec after notice time and 109 sec after trigger time at 2016-10-07 21:27:36 UT in two polarizations.. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box. The 5-sigma upper limit has been about 17.0 mag. The observations made on zenit distance = 68 degrees, galaxy latitude b = 11 degree. The moon (38 % bright part) below the horizon (The altitude of the Moon is -28 degree ). The message may be cited.