[vsnet-grb-info 7627] Swift-BAT trigger 349718 is not a burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9182
SUBJECT: Swift-BAT trigger 349718 is not a burst
DATE:    09/04/21 08:34:30 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at star.le.ac.uk>

P.A. Evans (U. Leicester), C.B. Markwardt (CRESST/GSFC/UMD) and J.
Greiner (MPE) report on behalf of the Swift team:

On 2009-04-21 at 07:30:19 UT Swift-BAT triggered on Swift trigger 34718.
Swift slewed to the location after short delay due to an Earth limb
constraint. The BAT on-board calculated location
is RA, Dec 311.382, -72.578 which is
    RA(J2000) = 20h 45m 32s
    Dec(J2000) = -72d 34' 38"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). This was a rate trigger with a very low image
significance (5.84 sigma).

XRT and UVOT began observations 6 minutes after the trigger; no
afterglow candidate is found.

Given the very low image significance (5.84 sigma) and the lack of
afterglow, we do not believe that this was a real GRB.