TITLE: GCN CIRCULAR NUMBER: 13225 SUBJECT: GRB 120404A: MITSuME Ishigakijima Optical Observation DATE: 12/04/05 09:17:32 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 120404A (Stratta et al., GCNC 13208) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2012-04-04 14:31:32 UT (~1.7 h after the burst). We detected the previously reported afterglow (Guidorzi et al., GCNC 13209) in only Ic band. Photometric results of the OT are listed below. We used SDSS catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic Ic_err ---------------------------------------------------------------------- 0.09215 15:03:44 1080.0 >18.6 >18.7 17.5 0.2 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]