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Reverted to revision 319282524 by BotKung; An official news release from the project has more authority than a "private communication". See: WP:RS. (TW)
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Undid revision 320151544 by Aldebaran66 (talk) As the former DPU project manager, I am well informed of what is going on.
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* <cite id="fn_a">[[#fn a back|Note a:]]</cite> The exact [[celestial coordinates]] and the standard catalog identifications for the parent stars have not been released for ''COROT-5b'' and ''COROT-6b'' as of 2009-07-31.
* <cite id="fn_a">[[#fn a back|Note a:]]</cite> The exact [[celestial coordinates]] and the standard catalog identifications for the parent stars have not been released for ''COROT-5b'' and ''COROT-6b'' as of 2009-07-31.


==Failure of photo-detector chain 1==
==Failure of Data Processing Unit #1==
On March 8, 2009 the satellite suffered a loss of communication with photo-detector chain number 1, one of the two photo-detector chains on the spacecraft. Science operations resumed early April with photo-detector chain number 1 offline and chain number 2 operating normally. The loss of photo-detector chain number 1 results in the loss of one [[Charge-coupled device|CCD]] dedicated to [[asteroseismology]] and one [[Charge-coupled device|CCD]] dedicated to planet detection. The [[field of view]] of the satellite is thus reduced by 50%. The loss of channel 1 appears to be permanent.<ref name="anomaly1">{{cite web
On March 8, 2009 the satellite suffered a loss of communication with Data Processing Unit #1, processing data from one of the two photo-detector chains on the spacecraft<ref>Private communication of Thierry Appourchaux of October 15, 2009</ref>. Science operations resumed early April with Data Processing Unit #1 offline while Data Processing Unit #2 operating normally. The loss of photo-detector chain number 1 results in the loss of one [[Charge-coupled device|CCD]] dedicated to [[asteroseismology]] and one [[Charge-coupled device|CCD]] dedicated to planet detection. The [[field of view]] of the satellite is thus reduced by 50%. The loss of channel 1 appears to be permanent.<ref name="anomaly1">{{cite web
| title=CoRoT back on track, on April 7th, 2009
| title=CoRoT back on track, on April 7th, 2009
| url=http://smsc.cnes.fr/COROT/GP_actualite.htm#042009
| url=http://smsc.cnes.fr/COROT/GP_actualite.htm#042009

Revision as of 05:36, 16 October 2009

For the French painter, see Jean-Baptiste-Camille Corot.
COROT
COSPAR ID2006-063A Edit this at Wikidata
SATCAT no.29678Edit this on Wikidata
Websitesmsc.cnes.fr/COROT
Start of mission
Launch date27 December 2006 14:24:00 UTC

COROT (COnvection ROtation and planetary Transits) is a space mission led by the French Space Agency (CNES) in conjunction with the European Space Agency (ESA) and other international partners. The mission's two objectives are to search for extrasolar planets with short orbital periods, particularly those of large terrestrial size, and to perform asteroseismology by measuring solar-like oscillations in stars.[1] It was launched at 14:28:00 UTC on 27 December 2006, atop a Soyuz 2.1b carrier rocket.[2][3][4] COROT subsequently reported first light on 18 January 2007.[5] COROT is the first spacecraft dedicated to extrasolar planet detection. It detected its first extrasolar planet, COROT-1b, in May 2007.[6] Mission flight operations were originally scheduled to end 2.5 years from launch but apparently flight operations have been extended to January, 2010.[7]

Overview

Spacecraft design

The COROT optical design minimizes stray light coming from the Earth and provides a field of view of 2.7° by 3.05°. The COROT optical path consists of a 27 cm (10.6 in) diameter off-axis afocal telescope housed in a two-stage opaque baffle specifically designed to block sunlight reflected by the Earth and a camera consisting of a dioptric objective and a focal box. Inside the focal box is an array of four CCD detectors protected against radiation by aluminum shielding 10mm thick. The asteroseismology CCDs are defocused by 760μm toward the dioptric objective to avoid saturation of the brightest stars. A prism in front of the planet detection CCDs gives a small spectrum designed to disperse more strongly in the blue wavelengths.[8]

The four CCD detectors are model 4280 CCDs provided by E2V Technologies. These are CCDs are frame-transfer, thinned, back-illuminated designs in a 2048 pixel by 2048 pixel array. Each pixel is 13.5 × 13.5μm2 in size which corresponds to an angular pixel size of 2.32 arcsec. The CCDs are cooled to −40 °C (233.2 K; −40.0 °F). 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°.[8]

The satellite, built in the Cannes Mandelieu Space Center, has a launch mass of 630 kg, is 4.10 m long, 1.984 m in diameter and is powered by two solar panels.[7]

Mission design

Over its planned 2½ year mission it will observe perpendicular to its orbital plane, meaning there will be no Earth occultations, allowing 150 days of continuous observation. During the northern summer it will observe in an area around Serpens Cauda and during the winter it will observe in Monoceros. During the remaining 30 days between the two main observation periods, COROT will observe 5 other patches of sky. Four fixed areas of the sky have been identified for study:

The probe will monitor the brightness of stars, watching for the slight dimming that happens in regular intervals when planets transit their primary sun. COROT will be sensitive enough to detect rocky planets several times larger than Earth; it is also expected to discover new gas giants, which currently comprise almost all of the known extrasolar planets.[9]

COROT will also undertake 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.

In each field of view there will be one main target star for the asteroseismology as well as up to nine other targets. Simultaneously, it will be recording the brightness of 12,000 stars brighter than apparent magnitude 15.5 for the extrasolar planet study. It is expected that a few dozen planets will be found as a result of this project.

The mission began on 27 December 2006 when a Russian Soyuz 2-1b rocket lifted the satellite into a circular polar orbit with an altitude of 827 km . The first scientific observation campaign started on 3 February 2007.[10]

Development

The primary contractor for the construction of the COROT vehicle was CNES,[11] to which individual components were delivered for vehicle assembly. The COROT equipment bay, which houses the data acquisition and pre-processing electronics, was constructed by the LESIA Laboratory at the Paris Observatory and took 60 person-years to complete.[11] The COROT camera, also constructed by the LESIA Laboratory, took 25 person-years to complete.[11]

Potential

Before the beginning of the mission, the team stated with caution that COROT would only be able to detect planets a few times to several times larger than Earth and that it was not specifically designed to detect habitable planets (it would instead assess their potential for habitability). According to the press release announcing the first results, COROT's instruments are performing with higher precision than had been predicted, and may be able to find planets down to the size of Earth.[6]

COROT should be assumed to only detect a small percentage of planets within its detection range due to the low percentage of existing planets that would likely make transits from the angle of observation from our Solar System. Expectations are that any planetary systems detected within a suitable range for further observations will be followed up by the future Darwin and Terrestrial Planet Finder spacecrafts or other projects like Kepler (NASA), New Worlds Mission, or Space Interferometry Mission.

Discoveries

On May 3, 2007, it was reported that COROT had discovered a hot Jupiter COROT-1b orbiting a sun-like star 1,500 light years away. This planet has a radius approximately 1.78 times that of Jupiter, a mass approximately 1.3 times that of Jupiter, and orbits its parent star once every 1.5 days.[6][12] On the 300th day of operations ESA reported that "CoRoT is discovering exo-planets at a rate only set by the available resources to follow up the detections".[13] On 20 December 2007, additional results were published, declaring that a second exoplanet, COROT-2b had been discovered, this time with a radius 1.4 times and a mass 3.5 times that of Jupiter. The orbital period is less than two days. Results on asteroseismology were published in the same press release.[14] Three papers describing the two exoplanets, with radial-velocity follow-up, appeared in Astronomy and Astrophysics in May 2008 (Barge 2008, Alonso 2008 and Bouchy 2008).

In May 2008, findings of two new exoplanets, as well as an unknown celestial object COROT-3b were announced by ESA. COROT-3b appears to be "something between a brown dwarf and a planet."

In February 2009, COROT-7b was announced. It is the smallest exoplanet to have its diameter confirmed at 1.7 Earth's diameter.

COROT scientists have indicated at the 2009 IAU meeting that they have evidence of as many as 80 planets including the seven already published, including multi-planet systems with up to five planets.[15]

COROT has found three far stars which show Sun-like seismology (oscillations and granulations), although hotter.[16]

Planets discovered by COROT

Seven planetary objects have been announced by the mission.

Star Constellation Right
ascension 		Declination App.
mag. 		Distance (ly) Spectral
type 		Planet Mass
(MJ) 		Radius
(RJ) 		Orbital
period
(d) 		Semimajor
axis
(AU) 		Orbital
eccentricity 		Inclination
(°) 		Discovery
year 		Ref
COROT-1 Monoceros 06h 48m 19s –03° 06′ 08″ 13.6 1560 G0V b 1.03 1.49 1.5089557 0.0254 0 85.1 2007
COROT-2 Serpens 19h 27m 07s +01° 23′ 02″ 12.57 930 G7V b 3.31 1.465 1.7429964 0.0281 0 87.84 2007
COROT-3 Aquila 19h 28m 13.265s +00° 07′ 18.62″ 13.3 2200 F3V b 21.66 1.01 4.25680 0.057 0 85.9 2008
COROT-4 Monoceros 06h 48m 47s −00° 40′ 22″ 13.7 F0V b 0.72 1.19 9.20205 0.090 0 90 2008
COROT-5 Monoceros?a 14 F9V b 0.459 1.28 4.0384 2008
COROT-6 Aquila?a 13.9 F5V b 3.3 1.16 8.89 2009
COROT-7 Monoceros 06h 43m 49.0s −01° 03′ 46.0″ 11.668 489 G9V b <0.066 0.150 0.853585 0.0172 0 80.1 2009 [17]

Notes

  • Note a: The exact celestial coordinates and the standard catalog identifications for the parent stars have not been released for COROT-5b and COROT-6b as of 2009-07-31.

Failure of Data Processing Unit #1

On March 8, 2009 the satellite suffered a loss of communication with Data Processing Unit #1, processing data from one of the two photo-detector chains on the spacecraft[18]. Science operations resumed early April with Data Processing Unit #1 offline while Data Processing Unit #2 operating normally. The loss of photo-detector chain number 1 results in the loss of one CCD dedicated to asteroseismology and one CCD dedicated to planet detection. The field of view of the satellite is thus reduced by 50%. The loss of channel 1 appears to be permanent.[19]

See also

References

  1. ^ "Europe goes searching for rocky planets" (Press release). ESA. 2006-10-26. Retrieved 2008-08-03.
  2. ^ "Successful launch of the COROT satellite, on 27 December 2006". COROT 2006 Events. CNES. 2007-05-24. Retrieved 2008-08-02.
  3. ^ Clark, Stephen (2006-12-27), "Planet-hunting space telescope launched", Spaceflight Now, Pole Star Publications, retrieved 2008-08-02
  4. ^ Bergin, Chris (2006-12-27). "Soyuz 2-1B launches with COROT". NASA SpaceFlight.com. Retrieved 2008-08-03.
  5. ^ Hellemans, Alexander (2007-01-18), "COROT sees first light", Physics World (online edition), IOP Publishing, retrieved 2008-08-02
  6. ^ a b c "COROT discovers its first exoplanet and catches scientists by surprise" (Press release). ESA. 2007-05-03. Retrieved 2008-08-02.
  7. ^ a b "COROT Satellite". COROT. CNES. 2006-09-18. Retrieved 2008-08-02.
  8. ^ a b Auvergne; et al. (2009). "The CoRoT satellite in flight: description and performances" (PDF). Submitted to Astronomy and Astrophysics. doi:10.1051/0004-6361/200810860. {{cite journal}}: Explicit use of et al. in: |author= (help)
  9. ^ Borde; et al. (2003). "Exoplanet detection capability of the COROT space mission" (PDF). Astronomy & Astrophysics. 405: 1137–1144. doi:10.1051/0004-6361:20030675. {{cite journal}}: Explicit use of et al. in: |author= (help)
  10. ^ "First scientific observations by Corot" (Press release) (in French). CNES. 2007-02-05. Retrieved 2008-08-02.
  11. ^ a b c "Completion and delivery of equipment bay and camera to CNES mark major project milestone" (Press release). Observatoire de Paris, CNES and CNRS-INSU. 2005-06-30. Retrieved 2008-08-03.
  12. ^ "Success for the first observations by the Corot satellite : An exoplanet discovered and first stellar oscillations" (Press release). CNRS. 2007-05-03. Retrieved 2008-08-02.
  13. ^ Jean Schneider (2008). "The Extrasolar Planets Encyclopaedia - COROT: 300 days in orbit" (PDF). CNRS/LUTH - Paris Observatory. Retrieved 2008-08-02. {{cite journal}}: Cite journal requires |journal= (help)
  14. ^ "COROT surprises a year after launch" (Press release). ESA. 2007-12-20. Retrieved 2008-08-02.
  15. ^ "Detecting habitable new worlds". The Economist. 2009-08-13. Retrieved 2009-08-13.
  16. ^ Michel, Eric (2008). "CoRoT measures solar-like oscillations and granulation in stars hotter than the Sun". Science. 322 (5901): 558–560. doi:10.1126/science.1163004. Retrieved 2009-03-22. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  17. ^ A. Léger, D. Rouan, J. Schneider, P. Barge, M. Fridlund, B. Samuel, M. Ollivier, E. Guenther, M. Deleuil, H.J. Deeg, M. Auvergne, R. Alonso, S. Aigrain, A. Alapini, J.M. Almenara, A. Baglin, M. Barbieri, H. Bruntt, P. Bordé, F. Bouchy, J. Cabrera,, C. Catala, L. Carone, S. Carpano, Sz. Csizmadia, R. Dvorak, A. Erikson, S. Ferraz-Mello, B. Foing, F. Fressin, D. Gandolfi, M. Gillon, Ph. Gondoin, O. Grasset, T. Guillot, A. Hatzes, G. Hébrard, L. Jorda, H. Lammer, A. Llebaria, B. Loeillet,, M. Mayor, M., T. Mazeh, C. Moutou, M. Pätzold, F. Pont, D. Queloz, H Rauer,, S. Renner, R. Samadi, A. Shporer, Ch. Sotin, B. Tingley, G. Wuchterl, Adda M., Agogu P., Appourchaux T., Ballans H.,, Baron P., Beaufort T., Bellenger R., Berlin R., Bernardi P., Blouin D., Baudin F., Bodin P., Boisnard L., Boit L., Bonneau F., Borzeix S., Briet R., Buey J.-T., Butler B., Cailleau D., Cautain R., Chabaud P.-Y., Chaintreuil S., Chiavassa F., Costes V., Cuna Parrho V., De Oliveira Fialho F., Decaudin M., Defise J.-M., Djalal S., Epstein G., Exil G.-E., Faur C., Fenouillet T., Gaboriaud A., Gallic A., Gamet P., Gavalda P., Grolleau E., Gruneisen R., Gueguen L., Guis V., Guivarc’h V., Guterman P., Hallouard D., Hasiba J., Heuripeau F., Huntzinger G., Hustaix H., Imad C., Imbert C., Johlander B., Jouret M., Journoud P., Karioty F., Kerjean L., Lafaille V., Lafond L., Lam-Trong T., Landiech P., Lapeyrere V., Larqu T., Larqu T., Laudet P., Lautier N., Lecann H., Lefevre L., Leruyet B., Levacher P., Magnan A., Mazy E., Mertens F., Mesnager J-M, Meunier J.-C., Michel J.-P., Monjoin W., Naudet D., Nguyen-Kim K., Orcesi J-L., Ottacher H., Perez R., Peter G., Plasson P., Plesseria J.-Y., Pontet B., Pradines A., Quentin C., Reynaud J.-L., Rolland G., Rollenhagen F., Romagnan R., Russ N., Schmidt R., Schwartz N., Sebbag I., Sedes G., Smit H., Steller M.B., Sunter W., Surace C., Tello M., Tiphéne D., Toulouse P., Ulmer B., Vandermarcq O., Vergnault E., Vuillemin A., and Zanatta P. (2009). "Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius" (PDF). Astronomy and Astrophysics (accepted).{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ^ Private communication of Thierry Appourchaux of October 15, 2009
  19. ^ "CoRoT back on track, on April 7th, 2009". Retrieved 2009-05-10.
  • "Europe goes searching for rocky planets" (Press release). ESA. 2006-10-26. Retrieved 2008-08-03.
  • Hellemans, Alexander (September 2007), "Dangling a COROT", Scientific American, vol. 297, no. 3, Scientific American, Inc., p. 32, retrieved 2008-08-03 Note: only first two paragraphs are free online
  • (Staff) (2007-12-26). "Space telescope to hunt planets". BBC News. BBC. Retrieved 2008-08-03. (subtitle) The French-led Corot mission has taken off from Kazakhstan on a quest to find planets outside our Solar System.

Mission pages

Peer-reviewed manuscripts: COROT discoveries

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