TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2726 SUBJECT: XRF040916: Optical Transient Candidate by Subaru DATE: 04/09/18 17:51:35 GMT FROM: George Kosugi at Subaru Telescope G. Kosugi, N. Kawai, A. Tajitsu, and H. Furusawa on behalf of the Subaru GRB Team: We have obtained Rc, Ic, and B-band images covering the entire error box for XRF040916 (=H4588, Yamazaki et al., GCN 2712; Yamamoto et al. GCN 2713) with SuprimeCam attached on the prime-focus of the Subaru 8.2m telescope atop Mauna Kea. We conducted a preliminary analysis and found a fading object located at coordinates: RA: 23:00:55.1 Dec: -05:38:43 J2000 The object was seen to fade in either of Rc, Ic, and B bands. Observing dates and tentative Rc-band magnitudes of OT are shown below. Photometric accuracy is roughly +/- 0.2 mag. -------------------------------------------- Date Magnitude(Rc-band) Sep.16, 5.6UT 22.3 Sep.16, 8.8UT 22.7 Sep.18, 11.8UT 24.8 This message may be cited.