TITLE: GCN CIRCULAR NUMBER: 10176 SUBJECT: GRB 091117: Gemini-North spectroscopy of DSS galaxy DATE: 09/11/19 11:01:41 GMT FROM: Ryan Chornock at UC Berkeley R. Chornock and E. Berger (Harvard) report: We obtained spectra of the DSS galaxy coincident with the XRT source (GCN 10173) seen in the Swift observations of the short GRB 091117 (GCN 10171) using GMOS on Gemini-North. A pair of 1800s exposures using the R400 grating were taken starting at 07:27 UT on Nov. 19. Numerous emission lines are present at z=0.096. The slit was aligned through both the nucleus and the point source on the spiral arm (GCN 10174). The off-nuclear point source exhibits the high-equivalent-width nebular emission lines expected of an H II region and is therefore unlikely to be related to the afterglow of GRB 091117. In addition, the nuclear spectrum shows a broad component to the H-alpha line (FWHM ~ 1670 km/sec), indicative of an AGN. The AGN could also be responsible for the observed X-ray emission.