TITLE: GCN CIRCULAR NUMBER: 11598 SUBJECT: GRB 110120A: MASTER optical observations DATE: 11/01/24 14:56:32 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, V.Shumkov, S.Shurpakov Sternberg Astronomical Institute, Moscow State University V.Krushinski, I.Zalozhnich, A. Popov Ural State University, Kourovka K.Ivanov, O.Chuvalaev, V.Poleschuk, E.Konstantinov, V.Lenok, O.Gres, S.Yazev, N.M.Budnev, Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk MASTER very wide field cameras (MASTER-Net: http://observ.pereplet.ru, 6 cameras 11 Mpix, 85, 1/1.2. 1 sec exposition, comonn FOW is 2400 square degrees) located in Kislovodsk was pointed to the GRB110120A 24 sec s after notice time and 64 sec after GRB time at 2011-01-20 16:00:42.913 UT. The sky near horizont is not clear. On our 60 coaded images we haven`t found optical transient within common area of the FERMI LAT error-box (Nicola Omodei et al., GCN Circ 11597) and (Hurley et al., GCN 11595). The 5-sigma upper limit has been about 10 mag (mean time = 94 sec after trigger). The image is available at http://observ.pereplet.ru/images/GRB110120A/grb.html The MASTER II telescopes FOW was out of the final error box and our previous results (Gorbovskoy et al., GCN Circ 11588) not valid. The observations was done at high zenith distance. mailto: lipunov@sai.msu.ru