TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5618 SUBJECT: GRB 060926: RTT150, UVOT afterglow candidate confirmation DATE: 06/09/26 20:18:53 GMT FROM: Irek Khamitov at TUG U. Kiziloglu (METU), I. Khamitov (TUG), Z. Aslan (TUG), E. Gogus (Sabanci Uni.), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI) I. Bikmaev, N. Sakhibullin (KSU/AST), report: We observed the field around the XRT error circle (Holland et al., GCN5612) of GRB060926 (Swift trigger 231231) with the Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), at the 17:45 UT of Sep 26, about 56 minutes after the burst. A series of frames (3*300sec) were taken in R band with TFOSC. At the position of UVOT afterglow candidate (GCN5612) we detect a faint source which faded more than 1 mag according to early detection (Stefanescu et al., GCN5614). Using USNO-B1 star (RA=17:35:42.06, DEC=+13:02:11.7, R2MAG=18.96) we estimate the following R magnitude for the source: t-t0 m_R err (min) 66.5 20.8 0.1 This message may be cited.