GCN Circular 11089
John O'Meara (Saint Michael's College), Hsiao-Wen Chen (UChicago), Jason X. Prochaska (UC Santa Cruz) report on behalf of a larger collaboration: "We observed the afterglow of GRB100814A reported by Schaefer et al. (GCN 11086) and confirmed by Gronwall et al. (GCN 11088) using the MagE echellette spectrograph on the Magellan Clay Telescope. The observations started at UT 04:46 on August 14, 2010, ~ one hour after the inital trigger. We obtained a 900s exposure. Our preliminary reduction shows that the afterglow spectrum displays absorption transitions due to AlIII, FeII, and MgII at redshift z=1.44, which we tentatively identify as the host redsdhift of the GRB. Further analysis is underway. This message may be cited."