Editing Neil Gehrels Swift Observatory (section)

=== X-ray Telescope (XRT) ===
[[File:Swift pre-launch.jpg|thumb|Swift before launch]]
The XRT <ref>{{cite journal|title=The Swift X-Ray Telescope|journal=Space Science Reviews|first=David N.|last=Burrows|display-authors=et al.|volume=120|issue=3–4|pages=165–195|date=October 2005 |doi=10.1007/s11214-005-5097-2|bibcode=2005SSRv..120..165B|arxiv=astro-ph/0508071|s2cid=54003617}}</ref> can take images and perform [[spectroscopy|spectral analysis]] of the GRB afterglow. This provides more precise location of the GRB, with a typical error circle of approximately 2 [[Minute and second of arc|arcseconds]] radius. The XRT is also used to perform long-term monitoring of GRB afterglow light-curves for days to weeks after the event, depending on the brightness of the afterglow. The XRT uses a [[Wolter telescope|Wolter Type I X-ray telescope]] with 12 nested mirrors, focused onto a single MOS [[charge-coupled device]] (CCD) similar to those used by the [[XMM-Newton]] EPIC MOS cameras. On-board software allows fully automated observations, with the instrument selecting an appropriate observing mode for each object, based on its measured count rate. The telescope has an energy range of 0.2–10 keV.<ref>{{cite web|url=http://swift.gsfc.nasa.gov/docs/swift/about_swift/xrt_desc.html|title=Swift's X-Ray Telescope (XRT) |publisher=NASA|date=August 15, 2008|access-date=May 2, 2009}} {{PD-notice}}</ref>