[vsnet-grb-info 13908] GRB 130912A: P60 Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15222
SUBJECT: GRB 130912A: P60 Observations
DATE:    13/09/12 21:02:47 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

S. B. Cenko (NASA/GSFC), V. Sudilovsky, M. Tanga, and J. Greiner (MPE
Garching), report on behalf of a larger collaboration:

We have imaged the field of the Swift short GRB130912A (D'Elia et al., GCN
15212) with the robotic Palomar 60 inch telescope in the r', i', and z'
filters.  Observations began at 8:48 UT on 2013 September 12 (13 min after
the Swift trigger).

Within the enhanced XRT error circle (Beardmore et al., GCN 15217) we
detect the faint source reported by Tanga et al. (GCN 15214) in all three
filters.  Using calibration stars from GROND, we measure an AB magnitude
of r' = 21.77 +/- 0.20 mag at a mean time of 8:58 UT and r' = 22.09 +/-
0.25 at 09:28 UT (23 and 53 min after the Swift trigger, respectively).
The lack of significant variability implies either a shallow afterglow
decay index, or this source may be the host galaxy of GRB130912A, as
suggested by Tanga et al. (GCN 15214).