TITLE: GCN CIRCULAR NUMBER: 17138 SUBJECT: GRB 141121A: Mondy optical observations DATE: 14/12/05 14:58:30 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), 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 continue observations of the field of GRB 141121A (Lien et al., GCN 17075) with AZT-33IK telescope of Sayan observatory (Mondy). We obtained several images in R-filter on Nov., 30, Dec. 1 - 2. In a combined image we detect optical afterglow (Tanga et al., GCN 17078; Perley et al., GCN 17081). A preliminary photometry of the OT is based on nearby SDSS DR9 stars: date UT start t-T0 Filter Exp. OT OT_err (mid, days) (s) 2014-11-30 18:45:29 9.7139 R 119*120 22.20 0.10 2014-12-01 18:35:23 10.6644 R 72*120 22.25* 0.17 2014-12-02 18:09:52 11.6606 R 92*120 22.40* 0.25 *)Due to bad seeing the photometry includes both afterglow and nearby source (Watson et al., GCN 17105; Mazaeva et al., GCN 17111).