TITLE: GCN CIRCULAR NUMBER: 22159 SUBJECT: GRB 171124A: MITSuME Akeno optical upper limits DATE: 17/11/24 14:58:20 GMT FROM: Katsuhiro L. Murata at Nagoya U K. Shiraishi, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, K. Morita, T. Ozawa, H. Mamiya, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 171124A (F. Longo et al., GCN Circular #22156) 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 2017-11-24 11:02:40.53 UT. We did not find any new point source within enhanced LAT circle in all three bands. We obtained following limits for the magnitudes. T0+[hour] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------ ------------------------------------------- ~6.38 12:00:00 300 >19.0 >18.5 >17.4 ------------------------------------------------------------ ------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used UCAC-4 catalog for flux calibration.