TITLE: GCN CIRCULAR NUMBER: 11972 SUBJECT: GRB110422A: MITSuME Ishigakijima Optical Observation DATE: 11/04/24 13:08:22 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (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 110422A (Mangano et al., GCNC 11957) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2011-04-23 12:44:54 UT, (~21 hours after the burst). We detected the previously reported afterglow (Klunko et al., GCNC 11958; Gres et al., GCNC 11960) in Rc band. Photometric results and three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Rc_err Ic ---------------------------------------------------------------------- 0.89834 13:15:32 2400.0 >21.0 20.9 0.3 >19.3 ---------------------------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] [GCN OPS NOTE(24apr11): Per author's request, the "110322" was changed to "110422A" in the first sentence.]