TITLE: GCN CIRCULAR NUMBER: 7661 SUBJECT: GRB080430: RTT150 Optical Observations DATE: 08/05/02 00:18:18 GMT FROM: Irek Khamitov at TUG I. Khamitov (TUG), I. Bikmaev, R. Gumerov, A. Nemtinov, N. Sakhibullin (KSU/AST), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.) report: The optical counterpart (GCN7646) of GRB 080430 (GCN 7647) was observed with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), starting at May 01, 21:58 UT, i.e. ~26.08 hours after the burst, using Andor CCD. A series of frames 3*300s in R and 3*600s in B bands were made. The afterglow is clearly detected in all images. Using USNO-B1 star (416-022819, RA=11:01:16.86, DEC=+51:40:38.5, B2MAG=17.79, R2MAG=16.61) we estimated the following magnitudes for the OT on combined images: t-t0 (h) band mag err 26.25 R 21.3 0.1 27.98 B 22.3 0.1 -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.