TITLE: GCN CIRCULAR NUMBER: 15949 SUBJECT: GRB 140311B: Nanshan afterglow detection DATE: 14/03/11 22:52:01 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), C.-H. Bai, X. Zhang, A. Esamdin, L. Ma (XAO) report: We observed the field of GRB 140311B (Racusin et al., GCN 15945) using the 1m telescope located in Nanshan, Xinjiang, China. Observations started at 21:41:05 UT on 2014-03-11 and some 300s/600s R-band frames were obtained. The afterglow is detected in each image within the XRT error circle (http://www.swift.ac.uk/sper/) at coordinates R.A. (J2000) = 16:49:17.97 Dec. (J2000) = +52:43:26.41 Uncertainty radius: ~1.5 aecsec The first 300s image reveals that the afterglow has m(R)=20.6 at 29.1 min post-burst, calibrated with nearby two SDSS stars. Observations are ongoing.