TITLE: GCN CIRCULAR NUMBER: 13230 SUBJECT: GRB 120404A: MASTER OT observations DATE: 12/04/06 16:00:51 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.Kuznetsov,A.Sankovich Moscow Lomonosov State University, Sternberg Astronomical Institute, 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 Blagoveschensk was pointed to the GRB120404A 24 sec after notice time and 71 sec after GRB time at 2012-04-04 12:52:13.917 UT (Yurkov et al., GCN 13210). The observations was made with a full moon and at high zenith distance. We see an OT (G. Stratta et. al., GCN 13208) on 3 single and some coadd images. First time the OT seen at coadd of six first images set with magnitude about 16.8. After this time the object was decay below 17.5 mag for an hour. The OT have a flash to 16.9 mag in our unfiltered band (0.8R+0.2B) ~ 1 h after trigger time. The detail imformation about observations in a table 1. Table 1. T_mid UT | T-T_grb sec.| Exptime | Coadd | Mag | err.mag ---------+-------------+---------+--------+------+-------- 12:55:25 | 263 | 180 | 6 | 16.8 | 0.3 13:46:14 | 3311 | 180 | 1 | 17.2 | 0.4 13:49:40 | 3517 | 180 | 1 | 16.9 | 0.4 13:56:33 | 3930 | 180 | 1 | 17.1 | 0.4 14:10:22 | 4760 | 900 | 5 | 17.8 | 0.3 14:36:13 | 6311 | 1800 | 10 | 18.1 | 0.3 15:21:03 | 9001 | 1800 | 10 | 18.2 | 0.3 ---------------------------------------------------------- The message may be cited.