[vsnet-grb-info 14619] Trigger 590503: Swift-BAT triggered on noise

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15933
SUBJECT: Trigger 590503: Swift-BAT triggered on noise
DATE:    14/03/05 23:38:37 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel at swift.psu.edu>

W. H. Baumgartner (GSFC/UMBC), V. D'Elia (ASDC),
C. B. Markwardt (NASA/GSFC), A. Maselli (INAF-IASFPA),
T. Sakamoto (AGU) and M. H. Siegel (PSU) report on behalf of the Swift
Team:

At 23:18:37 UT, the Swift Burst Alert Telescope (BAT) triggered (trigger=590503). 
Swift slewed immediately to the burst location. 
The BAT light curve showed a strongly rising background 
level as Swift entered the SAA.  Combined with the low significance image trigger
(5.81 sigma), we conclude that this trigger was caused by noise while entering 
the SAA. 

The XRT began observing the field at 23:20:52.7 UT, 135.7 seconds after
the BAT trigger. The only source detected is significantly outside the
BAT error circle and has the morphology of a cosmic ray. This is
therefore unlikely to be a real detection.