TITLE: GCN CIRCULAR NUMBER: 17622 SUBJECT: GRB 150323C: MASTER-net optical observation DATE: 15/03/23 17:22:58 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.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka 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 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) D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to the GRB150323C 42 sec after notice time and 88 sec after trigger time at 2015-03-23 17:09:39 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box (Amaral-Rogers et al. GCN17621). The 5-sigma upper limit has been about 17.6 mag MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Ural was pointed to the GRB150323C 35 after notice time and 79 sec after trigger time at 2015-03-23 17:09:31 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box (ra=12 50 28 dec=+50 11 25 r=0.001400). The 5-sigma upper limit has been about 17.9 mag The message may be cited.