TITLE: GCN CIRCULAR NUMBER: 5664 SUBJECT: GRB 060927 : GAO 150cm telescope optical observation DATE: 06/09/30 04:41:01 GMT FROM: Kenzo Kinugasa at Gunma Astro. Obs/Japan K. Kinugasa (Gunma Astronomical Observatory) and K. Torii (Osaka U.) report: The error region of GRB 060927 (Barbier et al., GCN 5627) was imaged by the LN2 cooled CCD camera atattched on the 150 cm telescope of the Gunma Astronomical Observatory. Starting at Sep.27 14:44:33 UT (37 min after the burst), thirty 30 s exposures in Rc band were obtained. In a stacked frame, the optical afterglow (Schaefer et al. GCN 5629) is detected and the magnitude is rouly estimated as follows relative to USNO-B1.0 R2 magnitude. ------------------------ MidUT Filter Mag ------------------------ 14:56 Rc ~20.3 ------------------------