TITLE: GCN CIRCULAR NUMBER: 9292 SUBJECT: GRB 090426: GAO 150cm telescope Optical Observation DATE: 09/04/29 14:27:50 GMT FROM: Kenzo Kinugasa at Gunma Astro. Obs/Japan K. Kinugasa, S. Honda, O. Hashimoto, H. Takahashi, H. Taguchi (Gunma Astronomical Observatory) report: The position of GRB 090426 (Cummings et al., GCN 9254) was observed with the 150 cm telescope of Gunma Astronomical Observatory. Starting at 13:20 and 13:48 UT (0.52 and 1.0 hours after the trigger), Ic and Rc frames were acquired for sets of 3 x 3-min and 5 x 5-min exposures, respectively. We detected the optical counterpart (e.g., Xin et al., GCN 9255; Oates et al., GCN 9265) in all frames. We estimated the Rc and Ic magnitudes relative to USNO-B1.0 R2 and I, respectively. mid-UT exp mag. ----------------------------------- 13:24:45 3x3min Ic=18.5+-0.3 14:03:58 5x5min Rc=19.9+-0.1 -----------------------------------