TITLE: GCN CIRCULAR NUMBER: 17649 SUBJECT: GRB 150323B: Khureltogot optical observations DATE: 15/03/27 19:01:34 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I.Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150323B (Cummings et al., GCN 17619) with ORI-40 telescope of Khureltogot observatory starting on Mar., 23 (UT) 16:06:11. We obtained 60 unfiltered images of 60 s exposure. Following detection of XRT sources (D'Avanzo et al., GCN 17634) we do not detect any source within XRT error circle of the source #1 up to a limiting magnitude 21.2. In particular we do detect the optical source found by Kelemen et al. (GCN 17643). At the position of XRT source #2 we found optical source which coincides with USNO star mentioned by Xin et al. (GCN 17638) and the star of SDSS DR9 catalog J172150.45+381700.1. Photometry of the sources is following Source# Date UT start t-T0 Filter Exp. mag. UL(3sigma) (mid, days) (s) 1 2015-03-23 16:06:11 0.29859 none 60*60 n/d 21.2 2 2015-03-23 16:06:11 0.29859 none 60*60 20.7+/-0.25 21.2 The photometry is based on R magnitudes of nearby SDSS DR9 stars SDSS9_id R(Lupton) J172146.77+381659.6 15.65 J172126.47+382201.1 18.14 J172127.98+382239.0 15.39