[vsnet-grb-info 12751] GRB 121226A: NOT optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14110
SUBJECT: GRB 121226A: NOT optical upper limit
DATE:    12/12/27 07:46:12 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

D. Xu (DARK/NBI), O. Smirnova, T. Purismo (NOT), J. P. U. Fynbo
(DARK/NBI), P. Jakobsson (U. Iceland) report on behalf of a larger
collaboration:

We observed the field of GRB 121226A (Krimm et al., GCN 14105) using
the 2.5m Nordic Optical Telescope (NOT) equipped with ALFOSC. We
obtained 3x600s R-band and 3x360s z-band images with their median time
of 06:14:49 UT on 2012-12-27 (i.e., 11.085 hr after the BAT trigger)
and 06:53:54 UT (i.e., 11.736 hr post-trigger), respectively.

No optical source was detected within the XRT error circle in both
R-and z-bands, down to a 3sigma limit of R~23.0 mag ,calibrated with
the USNO B1 catalogue.