GCN Circular 14059
Subject
GRB 121211A: Keck/LRIS redshift
Event
Date
2012-12-11T18:38:05Z (13 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech), J. X. Prochaska (UCO/Lick), and A. N. Morgan (UC
Berkeley) report:
We slewed with the Keck I telescope (+LRIS) to the location of GRB
121211A (Mangano et al., GCN 14057) immediately following the GCN
notice. The optical transient (Mangano et al.; Japelj et al., GCN
14058) was identified on the guider camera and longslit exposures began
at 14:01 UT, 14 minutes after the GRB trigger. After a single short
observation in low resolution we acquired 2x860s exposures on the blue
and red side. The spectral range extends from 3150-5630 and 5790-7440
Angstroms.
We identify FeII (2344, 2374, 2382, 2586, 2600) and possible FeII* and
MnII at a redshift of z=1.023, as well as a marginal detection of MgII
(2796, 2804) at the same redshift using the short initial exposure,
which covers the dichroic gap. We suggest this as the redshift of GRB
121211A.