[vsnet-grb-info 13930] GRB 130831A: RTT150 optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15244
SUBJECT: GRB 130831A: RTT150 optical observations
DATE:    13/09/23 12:08:11 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion at hea.iki.rssi.ru>

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.