[vsnet-grb-info 5992] Swift-BAT trigger 309665 is not a GRB

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7634
SUBJECT: Swift-BAT trigger 309665 is not a GRB
DATE:    08/04/20 13:32:43 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm at nasa.gov>

H.A. Krimm (CRESST/GSFC/USRA) and L. Vetere (PSU) report on behalf of 
the Swift Team:

The Swift-BAT trigger (trigger=309665) at 04:12:47 UT on 20 April 2008,
tentatively labelled GRB 080420 (GCN 7632, Vetere et al.),
is not due to a GRB or any other astrophysical source.  This trigger
is due to a cosmic ray shower event in the instrument.  All events
occurred in the same 100 microsec window.