TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2220 SUBJECT: GRB030329: RTT150 optical observations DATE: 03/05/09 14:50:05 GMT FROM: Irek Khamitov at TUG I.Bikmaev (KSU), I. Khamitov (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.  During the nights of May 3,4,7, 2003,  series of  5 and 15 min exposures with V-filter have been obtained under good photometric conditions and average seeing of 1.3 arcsec.  ANDOR TE 2048 x 2048 CCD has been used as the detector.   Results of OT our photometry (based on Henden's list, GCN 2082 ), averaged over for each night, are as follow:     Midtime  Vmag   Verr Total Exp. sec     03.86UT  21.40  0.07 10200   04.86UT  21.33  0.07 11400   07.86UT  21.60  0.08  9300   Additional note: Probably, a moved object was found in the vicinity of the OT. This object was labeled as "O2" in Zharikov et al. (GCN 2171) and as "A" in  Blake and Bloom (GCN 2011).   We integrated all the three night  observations into one image and  estimated the magnitudes of the sources  in the afterglow vicinity as                V      Verr   O1 (B) 23.0   0.2 O2 (A) 22.6   0.1   Using the coordinates of the reference stars   from Henden's list  we have determined the positions of OT  and O1, O2 as   RA(2000.0) DEC(2000.0)   OT 10:44:49.958 21:31:17.50 O1 10:44:50.039 21:31:10.86 O2 10:44:49.373 21:31:15.02   The comparision of coordinates with those given by Blake and Bloom has shown that position of the source "A" is different by 6 arcsec while  the  the position of the source "B" is in agreement  within  0.5 arcsec positional error of Blake and Bloom.   We estimate the color of O2 as  V-R = 0.2,  and of O1 as V-R = 0.9 (R mag estimates are taken from Khamitov et al., GCN 2198)   Taking into account the apparent magnitudes, color and considerable positional shift, we suppose that this is an object nearer to the Sun. Additional observations are encouraged.    This message may be cited.