TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3786
SUBJECT: Swift-BAT trigger 150131 is not a GRB
DATE:    05/08/13 07:00:17 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott@lheamail.gsfc.nasa.gov>

S. Barthelmy (GSFC), L. Barbier (GSFC), C. Markwardt (GSFC-UMD),
D. Palmer (LANL)
on behalf of the Swift-BAT team:

The Swift-BAT trigger (trigger=150131) at 04:40:48 UT on 13 Aug 2005
is not due to a GRB.  This was a long image trigger (16 min)
which had a s/c slew during the position calculation phase of the
on-board processing, and therefore used incorrect aspect information.

The initial series of GCN Notices were not distributed to the GCN client
list, because this incorrect aspect solution was recognized
by the GCN filtering code.  However, the s/c executed a delayed slew
to this position.  As as part of the slew process, the s/c issued
a SC_SLEW Notice which was not blocked by the GCN filtering code,
because the neccessary solution status information is not available
for delayed slews.  There were also the usual set of XRT and UVOT notices.
Hence the need for this retraction circular.

This retraction is for trigger 150131.  It should not be confused
with trigger 150139 which happened a few minutes ago.