[vsnet-grb-info 14341] GRB 140102A: Early optical observations from Nanshan

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15655
SUBJECT: GRB 140102A: Early optical observations from Nanshan
DATE:    14/01/03 00:07:27 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

D. Xu (DARK/NBI), X. Zhang, C.-H. Bai, H.-B. Niu, A. Esamdin, L. Ma
(XAO) report:

We observed the field of GRB 140102A (Hagen et al., GCN 15653) using
the 1m telescope located on Mt. Nanshan, Xinjiang, China, equipped
with a 1.2x1.2 deg^2 CCD camera. Observations started at 21:27:51 UT
on 2014-01-02 (i.e., 614s after the BAT trigger). All frames are in R
filter.

We find a decaying afterglow at the UVOT position, beginning with
R~16.3 mag at a mean time of 674s post-burst. The afterglow is
decaying roughly as F(t) ~ t^-1 up to ~7000s post-burst, possibly with
fluctuations in between. Observations are ongoing.

Photometry is calibrated with nearby stars: SDSS J140740.98+011949.8
and SDSS J140742.47+012010.4.