[vsnet-grb-info 14204] GRB 131127A: Nanshan optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15518
SUBJECT: GRB 131127A: Nanshan optical upper limit
DATE:    13/11/27 12:33:21 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

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

We observed the field of GRB 131127A (Markwardt et al., GCN 15516)
using 1m telescope located on Mt. Nanshan, Xinjiang, China.
Observations started at 11:45:12 UT on 2013-11-27 (i.e., 1.56 hr after
the BAT trigger) and a series of R-band frames were obtained.

Within the SPER XRT error circle (http://www.swift.ac.uk/sper/) of
this burst, no crediable optical source is detected down to a limiting
magnitude of R=20.5 mag, calibrated with nearby USNO B1 field.