TITLE: GCN CIRCULAR 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.