TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2791 SUBJECT: GRB 041006: Redshift confirmed DATE: 04/10/09 02:56:08 GMT FROM: Paul Price at IfA,UH P.A. Price (IfA, UH), K. Roth (Gemini), J. Rich, B.P. Schmidt, B.A. Peterson (RSAA, ANU), L. Cowie (IfA, UH), C. Smith and A. Rest (CTIO) report: We have observed the optical afterglow of GRB 041006 (GCN #2765) with the Gemini North Telescope + GMOS at 2004 Oct 7.36 UT. Observations consisted of 4 integrations of 1800 sec with the R400 grating and a 1 arcsec slit. Inspection of a single frame reveals absorption lines at 6750A and 6810A, which we interpret as corresponding to the Ca II H and K lines at a mean redshift of z = 0.716, in broad agreement with the redshift of z = 0.712 proposed by Fugazza et al. (GCN #2782). We thank the staff of Gemini North for performing these observations.