[vsnet-grb-info 13600] GRB 130625A: Nanshan optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14927
SUBJECT: GRB 130625A: Nanshan optical upper limit
DATE:    13/06/25 18:36:32 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

D. Xu (DARK/NBI), A. Esamdin, L. Ma, C.-H. Bai, G.-J. Feng (XAO) report:

We observed the field of GRB 130625A (Grupe et al., GCN 14923) using
the 1m telescope located at Mt. Nanshan, Xinjiang Astronomical
Observatory, China. We obtained 6x300s R-band frames with a mean time
of 15:40:08 UT on 2013-06-25, (i.e., 8.658 hr after the burst).

No optical source is detected within the enhanced XRT error circle
(Goad et al., GCN 14924) in the stacked image, down to a limit
magnitude of R=21.0 mag, calibrated with the USNO B1 catalog.