TITLE: GCN CIRCULAR NUMBER: 18308 SUBJECT: GRB 150911A: Mt. Terskol observatory upper limit DATE: 15/09/14 07:27:05 GMT FROM: Alexei Pozanenko at IKI M. Andreev (Terskol Branch of INASAN), E. Mazaeva (IKI), A. Sergeev (Terskol Branch of INASAN), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 150911A (Starling et al., GCN 18280) with Zeiss-600 telescope of Mt. Terskol observatory in R-filter starting on Sep. 11 (UT) 23:26:40. We do not detect any object within enhanced XRT error circle (Goad et al., GCN 18283). Photometry of the field is following Date UT start t-T0 Filter Exp. Upper_Limit (3sigma) (mid, days) (s) 2015-09-11 23:26:40 0.2273 R 40*120 21.7 Photometry is based on nearby USNO-B.1 stars USNO-B.1_id R2 0957-0043966 15.54 0957-0043954 16.24 0957-0043961 16.45