TITLE: GCN CIRCULAR NUMBER: 8713 SUBJECT: GRB 081222: Gemini-South absorption redshift DATE: 08/12/23 14:58:35 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko (Berkeley) and E. Berger (Harvard) report on behalf of a larger collaboration: Starting at 01:02 UT on 2008 December 23 we observed the optical counterpart of GRB 081222 (Grupe et al., GCN 8691, Covino et al., GCN 8692 and Updike et al. 8693) using Gemini-South with the GMOS-South spectrograph (R~1600). We acquired 2x900s spectra covering the wavelength range 4000A-8000A. We detect a damped Lyman-alpha system (DLA) at redshift z=2.77. We also detect several metal absorption features which we interpret as SiIV(1393,1402), SiII1526 and 1260, SiII*1264, CII1334, CII*1335, CIV(1548,1550), FeII1608 and NiII(1454) at the same redshift. In combination with the strong metal absorption features, the detection of a DLA at z = 2.77 confirms that this is the redshift of GRB 081222 and its host galaxy. We thank the Gemini staff, in particular Henry Lee, for conducting these observations.