TITLE: GCN CIRCULAR NUMBER: 17709 SUBJECT: GRB 150413A: GMG observation DATE: 15/04/16 04:29:34 GMT FROM: Jirong Mao at Yunnan Obs J. Mao, C. Wang and J.-M. Bai report: We observed the field of GRB 150413A (Markwardt et al., GCN 17688) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatory. Observations began from 13:35:29 UT, April 14, 2015, about 23.7 hours after the trigger. We marginally detected the optical counterpart and estimated the magnitude as I~20.3.