TITLE: GCN CIRCULAR NUMBER: 12818 SUBJECT: GRB 120106A: MASTER Early OT marginally detection DATE: 12/01/07 10:00:52 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich, S. Shurpakov Moscow State University, Sternberg Astronomical Institute K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev,E.Konstantinov, Irkutsk State University V.Krushinski, I.Zalozhnich, A. Popov Ural State University, Kourovka E. Sinykov, V.Yurkov, Yu.Sergienko, D.Varda, Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory MASTER II robotic double telescope (MASTER-Net: http://observ.pereplet.ru) located at Tunka (Baykal) was pointed to the 120106A (Immler et al., GCN Circ 12810) 19 s after notice time and 46 sec after GRB trigger time at 14:16:24.24 UT (Ivanov et al., GCN CIRC 12811). On our first (10s exposure) set we haven`t found optical transient within preliminary SWIFT XRT error-box (Immler et al., GCN Circ 12810). But we found marginally OT at East telescope (- polarizations) outside preliminary X-ray error box (Immler et al., GCN Circ 12810). The position of this OT is coincided with enhanced Swift-XRT position (Evans et al., GCN CIRC 12813). UT T-T_GRB Exp mag Tel Filter 2012-01-06 14:17:10 46 10 17.0+-0.3 East P- 2012-01-06 14:17:10 46 10 >16.8 West P| 2012-01-06 14:22:23 359 70 >18.0 East P- 2012-01-06 14:22:23 359 70 >18.0 West P| 2012-01-06 14:26:45 720 120 >18.2 East P- 2012-01-06 14:26:45 720 120 >18.2 West P| 2012-01-06 14:31:49 1024 180 >18.3 East P- 2012-01-06 14:31:49 1024 180 >18.4 West P| The images will be available at http://observ.pereplet.ru/images/GRB120106A/grb.html . The message may be cited.