TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2198 SUBJECT: GRB030329: RTT150 optical observations and upper limit for a host DATE: 03/05/03 14:59:53 GMT FROM: Irek Khamitov at TUG I. Khamitov (TUG), I.Bikmaev (KSU), M.Parmaksizoglu (TUG); N. Sakhibullin, V. Suleymanov (KSU); R. Burenin, R. Sunyaev, D. Denissenko, M. Pavlinsky, O. Terekhov, A. Tkachenko, M.Gilfanov (IKI); Z. Aslan, O.Golbasi (TUG); U. Kiziloglu, A. Alpar, A. Baykal (METU); report: We continue observations of the GRB 030329 optical afterglow (Peterson and Price, GCN 1985) with the 1.5-m Russian-Turkish Telescope RTT150 at TUG. A set of 18 exposures by 5 min. duration each with Rc Bessell filter has been obtained on the night May 02/03, 2003, under good photometric conditions and average seeing of 1.3 arcsec. A new TE Andor CCD with Marcony back-illuminated 2048 x 2048 chip was used as the detector with the working chip temperature -60 C. We grouped exposures by 3 frames and results of Rc photometry relative to the stars from Henden (GCN 2082) are given in the Table below. We integrated all exposures and made PSF subtraction from the OT's star-like structure to find the presence of the host galaxy. No object brighter than R ~ 23.5 mag was found at the position of the afterglow. A faint extended detail is seen at 1 arcsec west side of OT position on the residual image at the brightness level of limiting magnitude. The limiting magnitude is defined by fringe structures. We confirm the presence of two bright enough sources O1 and O2 at the 7 and 9 arcsec distances from OT indicated by S.Zharikov et al (GCN 2171) and estimated their magnitudes as R = 22.1 and 22.4 correspondingly. Table of Rc photometry UT R Rerr May 2.774 20.51 0.07 May 2.786 20.65 0.07 May 2.800 20.34 0.06 May 2.813 20.62 0.08 May 2.826 20.63 0.07 May 2.838 20.61 0.07 This message may be cited.