TITLE: GCN CIRCULAR NUMBER: 8065 SUBJECT: GRB080804: Gemini South redshift confirmation DATE: 08/08/05 15:34:42 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko (Caltech) and E. Berger (Harvard U.) report on behalf of a larger collaboration: Starting at 01:27 UT on 2008 August 5 we observed the optical counterpart of GRB 080804 (Rujopakarn et al., GCN 8056, Racusin et al., GCN 8057) using Gemini-South with GMOS spectrograph (R~1200). We acquired 2x900s spectra which covered the wavelength range 4000A-8000A and 2x900s spectra covering the range 6000A-10000A. We detect some of the metal absorption features identified by Thoene et al. (GCN 8058), like FeII (1608, 2260), NiII (1741 and 1751) and we also detect MgII doublet (2796,2803). We also detect part of the red wing of the Lyman break indicating a possible DLA associated with the grb host galaxy. All these features confirm that the grb redshift is z = 2.20. We thank the Gemini staff for conducting these observations.