TITLE: GCN CIRCULAR NUMBER: 10029 SUBJECT: GRB 091015: RTT150 optical observations DATE: 09/10/16 22:15:32 GMT FROM: Rodion Burenin at IKI, Moscow R. Gumerov, A. Nemtinov, I. Bikmaev, N. Sakhibullin (KSU/AST), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), M. Parmaksizoglu, I. Khamitov, Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.) report: The optical afterglow of GRB 091015 (Ferrigno et al., GCN 10025, Gotz et al., GCN 10026) was observed with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey) in partially cloudy conditions. We obtained a serie of 60s images in R centered at October 16, 17:40 UT, i.e. 0.76 days after the burst. The limiting magnitude in combined image is estimated as R=~22. We do not detect any new optical object as compared to DSS II red plate.