TITLE: GCN CIRCULAR NUMBER: 17183 SUBJECT: GRB 141212B: MITSuME Akeno upper limits DATE: 14/12/13 17:34:14 GMT FROM: Taketoshi Yoshii at Tokyo Tech Y. Yano, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, S. Kurita, Y. Ono, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 141212B (M. Stamatikos et al., GCN Circular #17159) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2014-12-12 19:31:43 UT (~6 h after the burst). We did not find any new point source within the enhanced XRT circle (K. L. Page et al., GCN Circular #17174) in all the three bands. The measured magnitudes are listed below. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------ 25180 20:31:06 840 >19.0 >18.8 >18.3 ------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.