TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4156 SUBJECT: GRB051022: host galaxy redshift DATE: 05/10/24 07:56:02 GMT FROM: Avishay Gal-Yam at Caltech A. Gal-Yam (Caltech), E. Berger (OCIW), D. B. Fox (Penn State), A. M. Soderberg, S. B. Cenko, P. B. Cameron (Caltech) and D. A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie collaboration: "We observed galaxy "B" (GCN 4143), located within the XRT error circle of the HETE GRB 051022 (GCN 4131; 4137; 4141) and coincident with the radio afterglow detected by Cameron et al. (GCN 4154), using the double spectrograph mounted on the 200" Hale telescope at Palomar Observatory. Preliminary reduction of a 3600s-long red spectrum of this galaxy reveals a strong line at observed wavelength 6736 Angstrom which we identify as OII 3727 at z=0.8. This identification is supported by weaker detections of OIII 5007 and 4959, as well as Hbeta and Hgamma. We conclude that the likely host of GRB 051022 is at z=0.8. Further analysis is underway."