Editing Neil Gehrels Swift Observatory (section)

== Instruments ==
=== Burst Alert Telescope (BAT) ===
[[File:Swift's instrument - diagram of Burst Alert Telescope (BAT).jpg|thumb|Diagram of Burst Alert Telescope]]
The BAT detects GRB events and computes its coordinates in the sky. It covers a large fraction of the sky (over one [[steradian]] fully coded, three steradians partially coded; by comparison, the full sky solid angle is [[Solid angle|4π]] or about 12.6 steradians). It locates the position of each event with an accuracy of 1 to 4 [[Minute and second of arc|arcminutes]] within 15 [[second]]s. This crude position is immediately relayed to the ground, and some wide-field, rapid-slew ground-based telescopes can catch the GRB with this information. The BAT uses a [[coded aperture|coded-aperture mask]] of 52,000 randomly placed {{cvt|5|mm}} [[lead]] tiles, {{cvt|1|m}} above a detector plane of 32,768 {{cvt|4|mm}} [[Cadmium zinc telluride]] (CdZnTe) hard X-ray detector tiles; it is purpose-built for Swift. Energy range: 15–150 [[Electronvolt|keV]].<ref>{{cite web|url=http://swift.gsfc.nasa.gov/docs/swift/about_swift/bat_desc.html|title=Swift's Burst Alert Telescope (BAT)|publisher=NASA|date=February 28, 2006|access-date=May 2, 2009}} {{PD-notice}}</ref>

=== 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>

=== Ultraviolet/Optical Telescope (UVOT) ===
[[File:M101 combined low.jpg|thumb|upright=1.0|left|UVOT's "[[first light (astronomy)|first light]]" image]]

After Swift has slewed towards a GRB, the [[Ultraviolet/Optical Telescope|UVOT]] is used to detect an optical afterglow. The UVOT provides a sub-arcsecond position and provides optical and ultra-violet photometry through lenticular filters and low resolution spectra (170–650&nbsp;nm) through the use of its optical and UV [[grism]]s. The UVOT is also used to provide long-term follow-ups of GRB afterglow lightcurves. The UVOT is based on the [[XMM-Newton]]'s Optical Monitor (OM) instrument, with improved optics and upgraded onboard processing computers.<ref>{{cite web |url=http://swift.gsfc.nasa.gov/docs/swift/about_swift/uvot_desc.html|title=Swift's Ultraviolet/Optical Telescope (UVOT)|publisher=NASA|date=December 14, 2006|access-date=May 2, 2009}} {{PD-notice}}</ref>

On 9 November 2011, UVOT photographed the asteroid [[(308635) 2005 YU55|2005 YU55]] as the [[asteroid]] made a close flyby of the [[Earth]].<ref>{{cite web|url=https://svs.gsfc.nasa.gov/vis/a010000/a010800/a010871/|title=Swift Captures Flyby of Asteroid 2005 YU55|publisher=NASA|date=November 11, 201|access-date=November 22, 2011|archive-date=5 March 2016|archive-url=https://web.archive.org/web/20160305021416/http://svs.gsfc.nasa.gov/vis/a010000/a010800/a010871/|url-status=dead}} {{PD-notice}}</ref>

On 3 June 2013, UVOT unveiled a massive ultraviolet survey of the nearby [[Magellanic Clouds]].<ref>{{cite web|url=https://www.nasa.gov/mission_pages/swift/bursts/magellanic-uv.html|title=NASA's Swift Produces Best Ultraviolet Maps of the Nearest Galaxies|publisher=NASA|date=June 3, 2013}} {{PD-notice}}</ref>

In August 2017, UVOT imaged UV emissions from gravitational wave event [[GW170817]] detected by LIGO & Virgo detectors.<ref>[https://www.nasa.gov/press-release/nasa-missions-catch-first-light-from-a-gravitational-wave-event ''NASA Missions Catch First Light from a Gravitational-Wave Event'' 2017] {{PD-notice}}</ref><ref name="Evans2017"/>