TITLE: GCN CIRCULAR NUMBER: 23891 SUBJECT: GRB190211A: MITSuME Akeno optical observation DATE: 19/02/12 11:18:29 GMT FROM: Motoki Oeda at Tokyo Inst. of Tech. M. Oeda, R. Itoh, K. L. Murata, Y. Tachibana, S. Harita, K. Morita, K. Shiraishi, K. Iida, M. Niwano, R. Adachi, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration We searched for the optical counterpart of GRB 190211A (F. E. Marshall et al., GCN Circular #23883) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 16:55:48.41 UT which corresponds to 64 sec after the trigger. We detected the point source at the position consistent with the robotic NEXT-0.6m telescope observation (D. Xu et al., GCN Circular #23884). The measured magnitudes are listed as follows. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------------------------------- ~64 16:56:48.41 120 ~18.3 ~17.7 ~17.0 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration. The magnitudes are expressed in the Vega system.