[vsnet-grb-info 15889] GRB 141212A: Gemini-N spectroscopy and photometry

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17177
SUBJECT: GRB 141212A: Gemini-N spectroscopy and photometry
DATE:    14/12/13 07:52:21 GMT
FROM:    Ryan Chornock at Ohio U  <chornock at ohio.edu>

R. Chornock (Ohio University), W. Fong (University of Arizona), and D. B. Fox 
(Penn State) report:

We obtained imaging and spectroscopy of the field of the short GRB 141212A 
(Ukwatta et al., GCN 17158) using GMOS on the 8 m Gemini-North telescope 
starting at 04:35 UT on 13 December, 16.4 hours after the BAT trigger.
In 5x180s of i-band imaging with 0.5" seeing, all three objects found by 
Malesani et al. (GCN 17170) are well detected.  Using an archival calibration, 
we measure i=22.2 +/- 0.1 mag for object A, the extended object present inside 
the enhanced XRT error circle (Osborne et al., GCN 17164).

In addition, we oriented a spectroscopic slit through both extended objects A 
and B (using the terminology of Malesani et al.).  We obtained 2x900s of 
spectroscopy with the R400 grating covering the wavelength range 5890-10100 
Angs.  Both galaxies exhibit prominent nebular line emission from [O II], 
H-beta, and [O III].  Galaxy A, the likely host, has a redshift of z=0.596, 
while Galaxy B has a redshift of z=0.672.