Editing CoRoT (section)

==Overview==

===Spacecraft design===

The CoRoT optical design minimized stray light coming from the Earth and provided a [[field of view]] of 2.7° by 3.05°. The CoRoT optical path consisted of a {{convert|27|cm|in|1|abbr=on}} diameter off-axis [[Afocal system|afocal]] telescope housed in a two-stage [[Opacity (optics)|opaque baffle]] specifically designed to block sunlight reflected by the Earth and a camera consisting of a [[dioptric]] [[objective lens|objective]] and a [[focal plane|focal box]]. Inside the focal box was an array of four [[Charge-coupled device|CCD]] detectors protected against [[Ionizing radiation|radiation]] by aluminum [[Radiation protection|shielding]] 10mm thick. The [[asteroseismology]] CCDs are defocused by 760μm toward the dioptric objective to avoid saturation of the brightest stars. A [[Prism (optics)|prism]] in front of the planet detection CCDs gives a small [[spectrum]] designed to disperse more strongly in the blue wavelengths.<ref name="design"/>
[[File:Corot Focal plane.jpg|thumb|The focal plane of CoRoT with its four full frame transfer CCD. The dark zone corresponds to the photo-sensitive area. Two CCDs are dedicated to the exoplanet programme and the two other ones to the asteroseismology programme.]]
The four [[Charge-coupled device|CCD]] detectors are model 4280 CCDs provided by [http://www.e2v.com/ E2V Technologies]. These CCDs are frame-transfer, thinned, back-illuminated designs in a 2,048 by 2,048 pixel array. Each pixel is {{nowrap|13.5 μm × 13.5 μm}} in size which corresponds to an angular pixel size of 2.32 arcsec.  The CCDs are cooled to {{convert|-40|C|K F|1|abbr=on}}. These detectors are arranged in a square pattern with two each dedicated to the planetary detection and [[asteroseismology]]. The data output stream from the CCDs are connected in two ''chains''. Each chain has one planetary detection CCD and one [[asteroseismology]] CCD. The [[field of view]] for planetary detection is 3.5°.<ref name="design">
{{cite journal |last1=Auvergne |first1=M. |date=2009 |title=The CoRoT satellite in flight: Description and performances |journal=[[Astronomy and Astrophysics]] |volume=506 |issue= 1|pages=411–424 |arxiv=0901.2206 |doi=10.1051/0004-6361/200810860 |bibcode=2009A&A...506..411A |s2cid=118466787 |display-authors=etal}}</ref>
The satellite, built in the [[Cannes Mandelieu Space Center]], had a launch mass of 630&nbsp;kg, was 4.10 m long, 1.984 m in diameter and was powered by two solar panels.<ref name="COROTSat">
{{cite web |date=18 September 2006 |title=COROT Satellite |url=http://smsc.cnes.fr/COROT/GP_satellite.htm |work=COROT |publisher=[[Cannes Mandelieu Space Center]] |access-date=2 August 2008}}</ref>

===Mission design===
{{update section|date=May 2016}}
The satellite observed perpendicular to its orbital plane, meaning there were no Earth [[occultation]]s, allowing up to 150 days of continuous observation. These observation sessions, called "Long Runs", allowed detection of smaller and long-period planets. During the remaining 30 days between the two main observation periods, CoRoT observed other patches of sky for a few weeks long "Short Runs", in order to analyze a larger number of stars for the asteroseismic program. After the loss of half the field of view due to [[failure]] of Data Processing Unit No. 1 in March 2009, the observation strategy changed to 3 months observing runs, in order to optimize the number of observed stars and detection efficiency.

In order to avoid the Sun entering in its field of view, during the northern summer CoRoT observed in an area around [[Serpens Cauda]], toward the [[Galactic Center]], and during the winter it observed in [[Monoceros (constellation)|Monoceros]], in the [[Galactic anticenter]]. Both these "eyes" of CoRoT have been studied in preliminary observations carried out between 1998 and 2005,<ref>{{cite web |url=http://media4.obspm.fr/exoplanetes/pages_corot-ciel/preparation.html |title=Les exoplanètes – Accueil |website=media4.obspm.fr}}</ref> allowing the creation of a [[database]], called CoRoTsky,<ref>{{cite web |url=http://smsc.cnes.fr/COROT/A_corotsky.htm |title=CoRoTsky Tool |website=smsc.cnes.fr}}</ref> with data about the stars located in these two patches of sky. This allowed selecting the best fields for observation: the exoplanet research program requires a large number of [[dwarf stars]] to be monitored, and to avoid [[giant star]]s, for which planetary [[Astronomical transit|transits]] are too shallow to be detectable. The asteroseismic program required stars brighter than magnitude 9, and to cover as many different [[Star classification|types of stars]] as possible. In addition, in order to optimize the observations, the fields had to not be too sparse – fewer targets observed – or too crowded – too many stars overlapping. 
Several fields were observed during the mission:<ref>{{cite web |url=http://idoc-corotn2-public.ias.u-psud.fr/invoquerSva.do?sva=browseGraph |title=CoRoT N2 Public Archive |first=IAS IT |last=department |website=idoc-corotn2-public.ias.u-psud.fr |access-date=10 April 2011 |archive-url=https://web.archive.org/web/20110818081746/http://idoc-corotn2-public.ias.u-psud.fr/invoquerSva.do?sva=browseGraph |archive-date=18 August 2011 |url-status=dead }}</ref>
*'''IRa01''', from 18 January 2007 to 3 April 2007 – 9,879 stars observed;
*'''SRc01''', from 3 April 2007 to 9 May 2007 – 6,975 stars observed;
*'''LRc01''', from 9 May 2007 to 15 October 2007 – 11,408 stars observed;
*'''LRa01''', from 15 October 2007 to 3 March 2008 – 11,408 stars observed;
*'''SRa01''', from 3 March 2008 to 31 March 2008 – 8,150 stars observed;
*'''LRc02''', from 31 March 2008 to 8 September 2008 – 11,408 stars observed;
*'''SRc02''', from 8 September 2008 to 6 October 2008 – 11,408 stars observed;
*'''SRa02''', from 6 October 2008 to 12 November 2008 – 10,265 stars observed;
*'''LRa02''', from 12 November 2008 to 30 March 2009 – 11,408 stars observed;
*'''LRc03''', from 30 March 2009 to 2 July 2009 – 5,661 stars observed;
*'''LRc04''', from 2 July 2009 to 30 September 2009 – 5,716 stars observed;
*'''LRa03''', from 30 September 2009 to 1 March 2010 – 5,289 stars observed;
*'''SRa03''', from 1 March 2010 to 2 April 2010;
*'''LRc05''', from 2 April 2010 to 5 July 2010;
*'''LRc06''', from 5 July 2010 to 27 September 2010;
*'''LRa04''', from 27 September 2010 to 16 December 2010;
*'''LRa05''', from 16 December 2010 to 5 April 2011;
*'''LRc07''', from 5 April 2011 to 30 June 2011;
*'''SRc03''', from 1 July 2011 to 5 July 2011 – a run made to reobserve the transit of [[CoRoT-9b]];
*'''LRc08''', from 6 July 2011 to 30 September 2011;
*'''SRa04''', from 30 September 2011 to 28 November 2011;
*'''SRa05''', from 29 November 2011 to 9 January 2012;
*'''LRa06''', from 10 January 2012 to 29 March 2012 – a run dedicated to reobservation of [[CoRoT-7b]];
*'''LRc09''', from 10 April 2012 to 5 July 2012;
*'''LRc10''', from 6 July 2012 to 1 November 2012 - interrupted by the fatal failure which ended the mission.

The spacecraft monitored the brightness of stars over time, searching for the slight dimming that happens in regular intervals when planets [[Astronomical transit|transit]] their host star. In every field, CoRoT recorded the brightness of thousands stars in the [[apparent magnitude|V-magnitude]] range from 11 to 16 for the extrasolar planet study. In fact, stellar targets brighter than 11 saturated the exoplanets CCD detectors, yielding inaccurate data, whilst stars dimmer than 16 do not deliver enough [[photon]]s to allow planetary detections. CoRoT was sensitive enough to detect [[rocky planet]]s with a radius two times larger than Earth, orbiting stars brighter than 14;<ref>{{cite journal |last1=Deleuil |first1=M. |last2=Moutou |first2=C. |last3=Bordé |first3=P. |year=2011 |title=The CoRoT Exoplanet program: status & results |journal=EPJ Web of Conferences |volume=11 |pages=01001 |doi=10.1051/epjconf/20101101001 |arxiv=1105.1887 |bibcode=2011EPJWC..1101001D}}</ref> it is also expected to discover new gas giants in the whole magnitude range.<ref name="detection">
{{cite journal |author1=P. Bordé |author2=D. Rouan |author3=A. Léger |date=2003 |title=Exoplanet detection capability of the CoRoT space mission |url=http://corot.oamp.fr/pub/corot_aa.pdf |journal=[[Astronomy and Astrophysics]] |volume=405 |issue=3 |pages=1137–1144 |arxiv=astro-ph/0305159 |bibcode=2003A&A...405.1137B |doi=10.1051/0004-6361:20030675 |s2cid=15577360 |url-status=dead |archive-url=https://web.archive.org/web/20071025063602/http://corot.oamp.fr/pub/corot_aa.pdf |archive-date=25 October 2007 }}</ref>

CoRoT also studied [[asteroseismology]]. It can detect [[luminosity]] variations associated with acoustic pulsations of stars. This phenomenon allows calculation of a star's precise mass, age and chemical composition and will aid in comparisons between the sun and other stars. For this program, in each field of view there was one main target star for asteroseismology as well as up to nine other targets. The number of observed targets have dropped to half after the loss of Data Processing Unit No. 1.

The mission began on 27 December 2006 when a Russian [[Soyuz 2 rocket|Soyuz 2-1b]] rocket lifted the satellite into a circular [[polar orbit]] with an altitude of 827&nbsp;km . The first scientific observation campaign started on 3 February 2007.<ref name="CNESPR2007">{{cite press release |title=First scientific observations by Corot |publisher=CNES |date=5 February 2007 |access-date=2 August 2008 |url=http://www.cnes.fr/web/5757-premieres-observations-scientifiques-de-corot.php |language=fr |archive-date=15 June 2008 |archive-url=https://web.archive.org/web/20080615042254/http://www.cnes.fr/web/5757-premieres-observations-scientifiques-de-corot.php |url-status=dead }}</ref>

The mission's cost amounted to {{€|170 million}}, of which 75% was paid by the French space agency [[CNES]] and 25% was contributed by Austria, Belgium, Germany, Spain, Brazil and the [[European Space Agency]] (ESA).<ref>{{cite web |url=http://www.dlr.de/dlr/PortalData/1/Resources/documents/2011_1/Broschuere_Corot_hires.pdf |title=CoRoT: Mission Brochur – Hunting for Planets in Space |work=DLR German Aerospace Center |publisher=DLR Institute of Planetary Research |date=February 2011 |archive-url=https://web.archive.org/web/20131024081457/http://dlr.de/dlr/Portaldata/1/Resources/documents/2011_1/Broschuere_Corot_hires.pdf |archive-date=24 October 2013 |url-status=dead |access-date=16 October 2012 }}</ref>