TITLE: GCN CIRCULAR NUMBER: 10389 SUBJECT: GRB 100206A - Keck/LRIS Spectroscopy DATE: 10/02/07 06:49:28 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko, J. S. Bloom, D. A. Perley, B. E. Cobb, A. N. Morgan, and A. A. Miller, Maryam Modjaz (UC Berkeley) and B. James (DARK) report on behalf of a larger collaboration: We have obtained spectra of the likely host galaxy (Miller et al., GCN 10377) and afterglow (Levan et al., GCN 10386) of the short-hard GRB100206A (Krimm et al, GCN 10376) with the Low Resolution Imaging Spectrometer mounted on the 10-m Keck I telescope. Observations began at 06:17 UT on 7 February (~ 16.8 hours after the burst) and cover the wavelength range from approximately 3500 - 10000 A. At the location of the candidate host galaxy, we detect a strongly red continuum consistent with the published photometry (Leloudas et al., GCN 10387). We detect strong, clearly resolved emission lines from H-alpha and [NII] at a redshift of z = 0.41. No other obvious lines are visible over spectral range in our preliminary reduction. The lack of H-beta, coupled with the red spectrum and colors, suggest a relatively dusty environment. At this redshift, the projected offset of ~ 6.8" from the candidate afterglow corresponds to a distance of ~ 35 kpc. No obvious trace is visible at the location of the afterglow. Observations and reduction are ongoing.