TITLE: GCN CIRCULAR NUMBER: 16131 SUBJECT: GRB 140419A: MITSuME Okayama Optical Observation DATE: 14/04/20 07:34:30 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (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 140419A (Marshall et al., GCNC 16118) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2014-04-19 11:17:09 UT (~7.2 h after the burst). We detected the previously reported afterglow (Marshall et al., GCNC 16118; Zheng et al., GCNC 16119) in Rc and Ic bands. Three sigma upper limit and photometric results of the OT are listed below. We used SDSS catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic Ic_err ----------------------------------------------------------------------- 0.36126 12:47:03 8700.0 >20.1 19.8 0.3 19.1 0.3 ------------------------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]