TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1475 SUBJECT: GRB 020813: Absorption redshift DATE: 02/08/13 09:18:37 GMT FROM: Paul Price at RSAA, ANU P.A. Price (RSAA, ANU), J.S. Bloom (Harvard/CfA, Caltech), R.W. Goodrich (Keck), A.J. Barth (Caltech), M.H. Cohen (Caltech) and D.W. Fox (Caltech) report: We have observed the afterglow of GRB 020813 (Fox, Blake & Price, GCN #1470) with LRIS in spectropolarimetry mode on Keck I at Aug 13.31 UT. We identify at an absorption system of Mg II, Mg I, Ca II, Fe II, Mn II at a redshift of z = 1.254 +/- 0.005. We identify a second absorption system at z = 1.222 +/- 0.005, based on Mg II, Mg I, Mn II. We conclude that the redshift of GRB 020813 is z >= 1.254. This message may be cited.