D. A. Perley (Caltech) and S. B. Cenko (GSFC) report:
Using the Low Resolution Imaging Spectrometer (LRIS) on the Keck I 10m
telescope, we acquired a single 900s spectrum of the optical afterglow
(Cenko et al., GCN 17612) of GRB 150323A (Amaral-Roger et al., GCN
17611) beginning at 06:11 UT, at the end of evening twilight.
A number of absorption and emission lines are detected in the 1D
spectrum, including e.g. Fe II (2344,2374,2383,2585,2599), Mg II
(2796,2803), Mg I (2853), OII (3727), OIII (4959, 5007), and H-beta at a
common redshift of z=0.593.
We acknowledge S. Kulkarni for the observing time.