TITLE: GCN CIRCULAR NUMBER: 13834 SUBJECT: GRB 121001A: MASTER optical observations DATE: 12/10/01 23:01:39 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, A.Sankovich, D.Denisenko Moscow Lomonosov State University, Sternberg Astronomical Institute, 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 A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnich, A. Popov, A. Bourdanov, A. Punanova Ural Federal University 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 Kislovodsk was pointed to the Swift GRB121001A 43 s after notice time and 209 sec after GRB time at 2012-10-01 18:26:31 UT in a two polarizations. We haven`t found optical transient within SWIFT error-box (D'Elia et al. GCN 13831) on our first (20 s exposure) set. The 5-sigma upper limit has been about 15.8 mag Observations were carried out under the full moon and on high zenith distance (~70 deg). Also a high stars density complicates the analysis. The data reduction is continued. The message may be cited.