GCN Circular 3999
Subject
Swift-BAT trigger 155764 is probably not a GRB
Date
2005-09-18T20:29:07Z (19 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
D. Grupe (PSU), S. Barthelmy (GSFC), D. Burrows (PSU), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), J. Kennea (PSU), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), P. Roming (PSU)
on behalf of the Swift team:
The Swift-BAT trigger (trigger=155764) at 19:42:13 UT on 18 Sep 2005
is probably not due to a GRB or any other astrophysical source.
We will have the full data set at 23:45 UT, after which we will issue
a final determination.
The spacecraft slewed immediately and the XRT began observing at 19:43:11
(at T+58s). The XRT generated an on-board centroid on a cosmic ray near
the edge of the field of view. This position is invalid (GCN 3998).
The spectrum and light curve are ambiguous, and we cannot rule out
the possibility of a weak afterglow in the XRT field of view.
Further analysis will require downloaded data following the next
ground station pass.
[GCN OPS NOTE(18sep05): Per author's request, the trigger number
in the subject line was corrected.]