TITLE: GCN CIRCULAR NUMBER: 16580 SUBJECT: Swift Trigger 604111 is not a GRB DATE: 14/07/12 03:18:33 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), J. A. Kennea (PSU), V. Mangano (PSU) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 02:58:30 UT, the Swift Burst Alert Telescope (BAT) triggered on a noise fluctuation on the rising background while entering the SAA. The XRT began observing the field at 03:00:00.6 UT, 89.9 seconds after the BAT trigger and centroided on a cosmic ray hit. Because this is a marginal significance BAT image peak, as Swift was entering the SAA, and there is no corresponding source at the correct location in XRT, we believe that this is not an astrophysical source.