TITLE: GCN CIRCULAR NUMBER: 12947 SUBJECT: GRB 120212A: MITSuME Ishigakijima Optical Observation DATE: 12/02/13 04:58:31 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 120212A (Sonbas et al., GCNC 12230) 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 2012-02-12 12:27:12 UT (~3.3 h after the burst). We detected the previously reported afterglow (Guidorzi et al.,GCNC 12932; Kawabata et al., GCNC 12935; Yanagisawa et al., GCNC 12936) in Rc and Ic bands. Photometric results of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic Ic_err ---------------------------------------------------------------------- 0.14653 12:42:22 780.0 >20.2 18.7 0.2 18.4 0.3 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]