TITLE: GCN CIRCULAR NUMBER: 4181 SUBJECT: GRB 051022: RTT150 optical observations DATE: 05/10/30 06:44:16 GMT FROM: Rodion Burenin at IKI, Moscow R. Burenin, D. Denisenko, M. Pavlinsky, R. Sunyaev (IKI), I. Khamitov, Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.), I. Bikmaev, N. Sakhibullin (KSU/AST) report: The error box of GRB 051022 (Olive et al., 4131; Tanaka et al., 4137) was observed with Russian-Turkish 1.5-m telescope (RTT150, Bakyrlytepe, TUBITAK National Observatory, Turkey) in R, starting at Oct. 22, 16:16 UT, i.e. 3.15 hours after the burst. The galaxy, where X-ray afterglow was detected with XRT (Racusin et al., GCN 4141) and later with Chandra (Patel et al., GCN 4163), appears in our images as clearly extended source. Its optical flux is stable within 0.1mag during our observations, i.e. till 20:00 UT, therefore we detected no variable source superimposed on this galaxy. This message may be cited.