GCN Circular 8774
A. Cucchiara and D. B. Fox (Penn State) report: "Starting on 2009 January 2.24 UT we used the Marcario LRS spectrograph on the Hobby-Eberly Telescope (R ~ 230) to obtain a 1000s spectrum of the optical afterglow of GRB 090102 (Mangano et al., GCN 8762, Covino et al., GCN 8763). The spectrum covers the wavelength range 4200 to 10,000 Angstrom. Unfortunately the data were taken under bad seeing conditions and the average S/N is ~5. Based on a preliminary calibration we detect some absorption features which we identify as the MgII doublet (2796,2803) and MgI(2856) at redshift z = 1.55. This value is consistent with the redshift reported by de Ugarte Postigo et al. (GCN 8766) and Cenko et al. (GCN 8773). We thank the HET staff for performing this observation, in particular John Caldwell."