TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5235 SUBJECT: GRB 060605: RTT150 optical observations DATE: 06/06/07 05:50:54 GMT FROM: Irek Khamitov at TUG I. Khamitov (TUG), A.T. Saygac (Ist.Uni), Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.), S.Alis, O.Onal (Ist.Uni) R. Burenin, M. Pavlinsky, R. Sunyaev (IKI) I. Bikmaev, N. Sakhibullin (KSU/AST), report: We observed the field around the position of the optical counterpart (Rykoff et al. GCN5220, Page et al., GCN5221) of GRB060605 (Swift trigger 213630) with the Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), at the beginning of June 07, about 31.1 hours after the burst. A series of frames was taken in R band with TFOSC. The afterglow is detected on combined image. http://www.tug.tubitak.gov.tr/~irekk/grb/grb060605/GRB060605_0607_RTT150.JPG Using USNO-B1 star (RA=21:28:40.26, DEC=-06:03:44.5, R2MAG=15.37) we estimate the following R magnitude for the OT: t-t0 m_R err 31.1 23.0 0.2 Using all data (Khamitov et al., GCN5224) we estimate the power-law decay index in R as -1.7+-0.02, which did not changed since ~5.6 hours after the burst. Our R lightcurve can be found at: http://www.tug.tubitak.gov.tr/~irekk/grb/grb060605/GRB060605_lc0607.jpg This message may be cited.