TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1183 SUBJECT: GRB 011130: Magellan spectroscopy DATE: 01/12/08 00:19:28 GMT FROM: Saurabh Jha at Harvard-Smithsonian CfA S. Jha, R. P. Kirshner, T. Matheson (CfA), P. M. Garnavich (Notre Dame), G. P. Monnelly, R. K. Vanderspek and G. R. Ricker (MIT) report: We obtained a spectrum of the optical counterpart to the radio source (GCN 1173) that is a possible afterglow to GRB 011130 (GCN 1179) with the Magellan 6.5m Baade telescope (+ LDSS2) on Dec. 7.15 (UT). Four 1200s exposures have a resolution of 1.2 nm and cover the wavelength range 400 to 800 nm. The spectrum of the source reported on GCN 1179 is dominated by galaxy light. A strong calcium break is seen at 600 nm providing a redshift of z=0.50. No significant [OII] is detected. The brighter galaxy 4" east was also placed on the slit and has the same redshift. This message may be cited.