TITLE: GCN CIRCULAR NUMBER: 17671 SUBJECT: GRB 150323C: CrAO optical observations DATE: 15/04/04 11:23:31 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), K. Antoniuk (CrAO), E. Mazaeva (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the GRB 150323C (Amaral-Rogers et al., GCN 17621) with AZT-11 telescope of CrAO observatory starting on Mar. 23 (UT) 20:09:58. We obtained ages in R-filter of 180 s exposure under non-optimal weather conditions and mean FWHM of about 4.7 arcsec. In the enhanced XRT position (Osborne et al., GCN 17633) we do not detect any object. In particular we do no detect optical afterglow (Xu et al. GCN 17625, Xin et al. GCN 17631; Watson et al. GCN 17632). An upper limit is following Date UT start, t-t0 Filter Exp. OT UL (3 sigma) (mid, days) (s) 2015-03-23 20:09:58 0.14949 R 20*180 n/d 21.0 The photometry is based on nearby USNO-B1.0 stars.