TITLE: GCN CIRCULAR NUMBER: 15995 SUBJECT: GRB 140311B: Mondy optical limit DATE: 14/03/18 20:45:27 GMT FROM: Alexei Pozanenko at IKI, Moscow A.Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 140311B (Racusin et al., GCN 15945) with AZT-33IK telescope of Mondy observatory starting on Mar. 12 (UT) 20:21:16. Within enhanced Swift-XRT eror circle (Evans et al., GCN 15958) we do not detect the optical afterglow (Xu et al., GCN 15949). Details of the photometry is following: date UT start t-T0 Exp. Filter UpperLimit (3sigma) (mid, days) (s) 2014-03-12 20:21:16 0.98389 30x120 R 20.2 The photometry is based on reference star SDSS-DR9, (R mag, transformation by Lupton 2005): N SDSS_id R(Lupton) err J164910.91+524333.6 17.449 0.009