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.