TITLE: GCN CIRCULAR NUMBER: 26615 SUBJECT: GRB 191228A: Mondy optical upper limit DATE: 19/12/30 15:53:01 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), E. Klunko (ISTP), N. Pankov (HSE), K. Kamyshnikov (HSE), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of IKI-GRB-FuN: We observed the field of GRB 191228A (Bernardini et al. GCN 26601) with AZT-33IK telescope of Sayan observatory (Mondy) starting on Dec. 28 (UT) 11:15:09. We do not detect any optical object in the Enhanced Swift-XRT position (Evans et al. GCN 26606). Preliminary photometry of the field is following. Date UT start t-T0 Filter Exp. OT UL(3sigma) (mid, days) (s) 2019-12-28 11:15:09 0.48923 R 30*120 n/d 20.1 Photometry is based on the USNO-B2.0 nearby stars.