TITLE: GCN CIRCULAR NUMBER: 12517 SUBJECT: Swift-BAT trigger 506884 is not a GRB DATE: 11/11/03 04:20:54 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), E. A. Hoversten (PSU), F. E. Marshall (NASA/GSFC), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU) and M. C. Stroh (PSU) report on behalf of the Swift Team: At 03:28:08 UT 03 Nov 2011, Swift-BAT triggered as a result of the star tracker having lost lock. This trigger is not due to a GRB or anything astrophysical. Only one GCN Notice type (the Quick_Look type that goes to robotic telescopes) was distributed to the world. All the rest of the notice types were automatically blocked-to-world for Image triggers that occur during a period of star tracker loss-of-lock. But the Quick-Look notice is produced before any information is received that it is an Image trigger.