TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3962 SUBJECT: GRB 050911: z~0.16 cluster in the field DATE: 05/09/11 16:50:31 GMT FROM: Edo Berger at Carnegie Obs E. Berger (Carnegie Observatories) reports: "The position of GRB 050911 is located about 3.5 arcmin from the center of a galaxy cluster (EDCC 493; diameter ~ 20 arcmin). Several galaxies in this field have a redshift of about 0.165, measured in the Las Campanas Redshift Survey (LCRS). If GRB 050911 is a short burst (as may be indicated by the initial short duration pulses; GCN 3961), then it is possible that it is associated with EDCC 493, and is therefore located at z~0.16. We note that the prompt emission exhibits a second peak at t+10 to t+20 sec (GCN 3961), but this may be a softer component as observed in GRBs 050709 and 050724."