[vsnet-grb-info 13003] GRB 130327A: Weihai optical obsevations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14340
SUBJECT: GRB 130327A: Weihai optical obsevations
DATE:    13/03/27 17:51:32 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

D. Xu (DARK/NBI), C. Cao, S. M. Hu (SDU) report:

We observed the field of GRB 130327A (Ukwatta et al., GCN 14331) using
the 1m telescope located in Weihai, Shandong Province, China.
Observations started at 11:27:02 UT on 2013-03-27 (i.e, 9.658 hr after
the burst) in a seeing of ~2.8", and 10x360s I-band images were
obtained with a mean time of 10.158 hr post-burst.

Within the enhanced XRT error circle (Osborne et al., GCN 14335), no
credible source is detected in the stacked I-band image, down to a
limit of R>20.2 mag, calibrated with the USNO B1 catalogue.

A source, with R~19.2 mag and somehow extended along NW-SE, is
detected at the position of the "second uncatalogued source" reported
by Butler et al. (GCN 14334), and confirmed in Elenin et al. (GCN
14337). This source might be the one in Morgan (GCN 14333). Since it
is 5.5" away from the center of the enhanced XRT error circle (radius:
1.9") and it's getting brightening significantly, this source is
unlikely related to the afterglow of the burst.

We thank Dayong Ren for carrying out thee observations.