TITLE: GCN CIRCULAR NUMBER: 16176 SUBJECT: GRB 140423A: MITSuME Akeno upper limits DATE: 14/04/28 12:03:53 GMT FROM: Taketoshi Yoshii at Tokyo Tech Y. Ono, Y. Tachibana, Y. Saito, H. Ohuchi, T. Yoshii, S. Kurita, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We performed the follow-up observation for optical afterglow of GRB140423A(E.Sonbas et al., GCN Circular #16142, Elenin et al.,GCN Circular #16143 etc.) 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 2014-04-24 14:10:46 UT (31.1h after the burst). We did not find the optical source on the position of GRB140423A. The measured magnitudes were listed below. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------- 44700 14-04-24 15:42:02 9600 >21.3 >21.2 >20.6 ------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.