TITLE: GCN CIRCULAR NUMBER: 14322 SUBJECT: GRB 130313A: optical upper limit in CrAO DATE: 13/03/16 19:54:45 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 130313A (Gompertz et al., GCN 14293) with ZTSh telescope of CrAO observatory (Mondy) on March 14 between (UT) 00:23:52 - 02:11:00. We took several images in R-filter of 60 s exposure which cover the refined BAT error box (Barthelmy et al., GCN 14296). Within XRT position (Gompertz et al., GCN 14297; Osborne et al., GCN 14300) we do not detect any source. Preliminary photometry of a combined image is following UT start, t-t0 filter Exp. OT UL (3 sigma) (mid, days) (s) 00:23:52 0.3818 R 24x60 n/d 22.7 The photometry is based on USNO-B1.0 star 0896-0256107 15:45:37.83 -00:22:18.2 R=16.04