TITLE: GCN CIRCULAR NUMBER: 14499 SUBJECT: GRB 130427B: MITSuME Ishigakijima upper limits DATE: 13/04/29 06:41:41 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 130427B (Maselli et al., GCNC 14460) 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 2013-04-28 18:47:24 UT (~1.23 days after the burst). We did not find any new point source within the enhanced XRT circle (Osborne et al., GCNC 14467) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 1.25418 19:26:42 3540.0 >20.6 >20.7 >20.1 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]