TITLE: GCN CIRCULAR NUMBER: 18644 SUBJECT: GRB 151127A: LCOGT-SSO optical upper limits DATE: 15/11/27 12:51:46 GMT FROM: Dong Xu at NAOC/CAS D. Xu (NAOC/CAS), D. Malesani (DARK/NBI), Y. Qin (Geneva Observatory), Y.-H. Han (NAOC/CAS, HUST), and Y.-D. Hu (IAA-CSIC) report: We observed the field of the short GRB 151127A (D'Ai et al., GCN 18643) with the 1-m LCOGT telescope at the Siding Spring Observatory. Observations started 27.42 UT on 2015-11-27 (i.e., 1.04 hr after the GRB), and we obtained 5x180s R-band and 8x180s I-band images. No new source is detected inside or close to the XRT position (D'Ai et al., GCN 18643), down to 3-sigma upper limits of R > 20 mag and I > 19 mag (calibrated against nearby USNO stars), at mean times of 1.17 and 1.52 hr after the GRB, respectively.