TITLE: GCN CIRCULAR NUMBER: 8978 SUBJECT: Swift trigger 346250 is probably not a burst DATE: 09/03/12 06:52:08 GMT FROM: Hans Krimm at NASA-GSFC H. A. Krimm (CRESST/GSFC/USRA), E. A. Hoversten (PSU), C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester) and L. Vetere (PSU) report on behalf of the Swift Team: On 2009-03-12 at 06:17:00 UT, the Swift Burst Alert Telescope (BAT) triggered on Swift trigger 346250. Swift did not slew immediately to the event due to an earth-limb constraint. The BAT on-board calculated location is RA, Dec 282.112, +36.758 which is RA(J2000) = 18h 48m 27s Dec(J2000) = +36d 45' 28" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed nothing significant. Given the low significance (5.72 sigma) we do not believe that this event is a real GRB. Swift will not be able to observe with the Swift narrow-field instruments until ~48 minutes after the trigger.