TITLE: GCN CIRCULAR NUMBER: 9841 SUBJECT: GRB090817: Keck/LRIS Spectroscopy DATE: 09/08/26 08:22:47 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko, L. M. Walkowicz (UC Berkeley), M. M. Kasliwal, V. Bhalero, S. R. Kulkarni, F. A. Harrison (Caltech), I. Arcavi (Weizmann Institute) and W. H. Baumgartner (GSFC/UMBC) report on behalf of a larger collaboration: We have obtained a spectrum of the putative host galaxy of GRB09817 (Holland et al., GCNs 9831 and 9834) with the Low Resolution Imaging Spectrometer mounted on the 10 m Keck I telescope. Our spectra were taken in twilight conditions at Aug 25.55 UT and cover a wavelength range from 3500 - 9000 A. After correcting for the large Galactic extinction, the source exhibits a blue continuum with superposed absorption features from the H Balmer series (H-alpha, -beta, -gamma, and -delta) and Ca (H+K and the NIR triplet), all consistent with their rest wavelengths. As suggested by Halpern and Ruan (GCN 9837), the object is therefore a foreground star (likely a hot, ~ A-type) and likely unrelated to GRB090817.