TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4306 SUBJECT: Swift-BAT trigger 165579 is not a GRB DATE: 05/11/27 17:45:41 GMT FROM: Scott Barthelmy at NASA/GSFC S. Barthelmy (GSFC) and C. Markwardt (GSFC/UMD) on behalf of the Swift-BAT team: The Swift-BAT trigger (trigger=165579) at 14:06:43 UT on 27 Nov 2005 (reported in O'Brien et al GCN 4305) is not due to a GRB or any other astrophysical source. The BAT mask-tagged lightcurve shows no significant emission on time scales ranging from 100 microsec to several seconds.