TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4186 SUBJECT: GRB 051016B host spectroscopy and redshift DATE: 05/11/02 19:10:28 GMT FROM: Alicia Soderberg at Caltech A. M. Soderberg, E. Berger and E. Ofek report on behalf of the Caltech-NRAO-Carnegie collaboration: "We observed the optical afterglow position (GCN 4105) of GRB 051016B (GCN 4103) with the Low Resolution Imaging Spectrometer on the Keck I telescope on 2005 October 31.6 UT. We detect an extended source in the g and r filters which we identify as the host galaxy. In a 900 sec spectrum we detect emission lines of [O II] and Ne III, at a redshift of z=0.9364."