[vsnet-grb-info 16313] GRB 150317A: Enhanced Swift-XRT position

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17594
SUBJECT: GRB 150317A: Enhanced Swift-XRT position
DATE:    15/03/17 08:03:37 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the
Swift-XRT team:

Using 2091 s of XRT Photon Counting mode data and 2 UVOT images, we find 
an astrometrically corrected X-ray position (using the XRT-UVOT 
alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, 
Dec = 138.98467, 55.46618 which is equivalent to:

RA  (J2000):  09h 15m 56.32s
Dec (J2000): +55d 27' 58.2"

with an uncertainty of 2.2 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. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.