GCN Circular 8818
Subject
GRB090117: Swift-XRT detection of a possible candidate afterglow
Date
2009-01-18T00:04:10Z (16 years ago)
From
Andy Beardmore at U Leicester <apb@star.le.ac.uk>
A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team :
The Swift-XRT began observing the field of the SuperAGILE GRB 090117 at
2009-01-17 19:10:13 UT, 13.7 ks after the burst. In a 1.9 ks Photon
Counting mode X-ray image covering the 0.3-10 keV band, we detect an
uncatalogued source within the SuperAGILE error circle at the
astrometrically corrected X-ray position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue) of RA, Dec =
164.0444, -58.2336 which is equivalent to:
RA (J2000): 10 56 10.66
Dec (J2000): -58 14 00.8
with an uncertainty of 2.4 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. The
position enhancement is described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is
an extension of this method.
At this stage we cannot tell if the source is fading to confirm that it
is the X-ray counterpart of the SuperAGILE burst.
This circular is an official product of the Swift-XRT team.