GCN Circular 15244
G. Khorunzhev, R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), I. Bikmaev, N. Sakhibullin (KFU/AST), I. Khamitov, H. Kirbiyik (TUG) report: The optical afterglow of GRB 130831A (GCN 15139, D. Palmer) was observed with 1.5-m Russian-Turkish Telescope RTT150 at Bakyrlytepe (TUBITAK National Observatory, Turkey). The observation started at 2013-09-01 00:42:03 UT, appr. 12 hours after the burst. Two images each with exposure 300 seconds were obtained in R-band: 1. UT = 00:42:03.678; t-t0 = 11.630h; m_R = 19.57 +- 0.02 2. UT = 00:48:35.373; t-t0 = 11.739h; m_R = 19.62 +- 0.03 Images are calibrated using stars proposed by Pozanenko et al. (GCN 15190). The magnitudes are not corrected for the Galactic extinction.