TITLE: GCN CIRCULAR NUMBER: 12048 SUBJECT: GRB 110530A: MITSuME Akeno Optical Observation DATE: 11/05/30 16:54:31 GMT FROM: Yoichi Yatsu at Tokyo Tech. Y. Yatsu, K.Kawakami, Y. Aoki, K. Tokoyoda, M. Hayashi, S. Song, R. Usui, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed GRB110530A (D'Avanzo et al, GCN12046) with the optical three color (g, Rc, and Ic) CCD camera attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The follow-up observation was started at 15:31:02, ~2min after the BAT trigger. And we detected a very faint object within the XRT error circle in R-band. The measured R-band magnitude is shown below. T0+[s] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------------------------- 125 15:39:42 660 --- 18.84 +/- 0.65 --- ----------------------------------------------------------------------- T0+ : Elapsed time after the burst [sec] T-EXP: Total Exposure time [sec] Photometric results and are listed below. We used GSC2.3 catalog for flux calibration.