[vsnet-grb-info 8472] GRB 091003: UVOT-enhanced XRT position

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9988
SUBJECT: GRB 091003: UVOT-enhanced XRT position
DATE:    09/10/04 12:10:23 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1 at star.le.ac.uk>

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

Using 4881 s of XRT Photon Counting mode data and 11 UVOT 
images for GRB 091003, 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 =
251.51980, 36.62470 which is equivalent to:

RA (J2000):  16 46 4.75
Dec (J2000): +36 37 29.0

with an uncertainty of 1.7 arcsec (radius, 90% confidence). The UV 
counterpart reported in Gronwall & Starling (GCN Circ.9987) is consistent 
with this position.

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.