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GCN Circular 8818

GRB090117: Swift-XRT detection of a possible candidate afterglow
2009-01-18T00:04:10Z (15 years ago)
Andy Beardmore at U Leicester <>
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 The
position  enhancement is described by Goad et al. (2007, A&A, 476, 1401, 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.
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