GCN Circular 14059
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.