GCN Circular 17830
J. Mao, X. Zhang and J. Bai (YNAO) report: We observed the Swift-XRT field of GRB 150518A (Sbarufatti et al., GCN 17827) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatory. Observations began from 16:02:40 UT, May 19, 2015, about 18.3 hours after the trigger. At the position of RA=15:36:48.27 DEC=16:19:47.1, we clearly detect one source with roughly estimated magnitude r'~21.2+/- 0.1. We could not distinguish the SDSS galaxy noticed by Xu et al. (GCN 17829) and the afterglow at this position. Detailed analysis is ongoing. We thank D. Xu for his kind information.