TITLE: GCN CIRCULAR NUMBER: 8346 SUBJECT: GRB 081008: Gemini-South Absorption Redshiftt DATE: 08/10/09 04:15:43 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 00:20 UT on 2008 October 9 (T0+5h) we observed the optical counterpart of GRB 081008 (Racusin et al., GCN 8344, Rykoff et al., GCN 83433) using Gemini-South with the GMOS-South spectrograph (R~1600). We acquired 2x900s spectra covering the wavelength range 3800A-6700A. We clearly detect several metal absorption features which we interpret as SiIV(1393,1402), SiII1526, SiII*1816, CIV(1548,1550), FeII1608, AlII1670, NiII1703, AlIII(1854,1862), MgI2026 at the common redshift of z = 1.967. The absorption system identified by D'Avanzo et al. (GCN 8345) can be explained by the CIV and SiII/SiII* doublets at this redshift. We thank the Gemini staff for conducting these observations.