CoRoT-2b explained

CoRoT-2b
Discoverer:CoRoT mission
Discovery Site:Earth's orbit
Discovered:2007-12-??,
announced 2007-12-20
Discovery Method:Transit method
Apsis:astron
Semimajor:0.0281±
Eccentricity:0 (assumed)
Inclination:87.84 ± 0.10
Star:CoRoT-2
Mean Radius:1.429 ± 0.047
Mass:3.31 ± 0.16
Density:1310±
Surface Grav:38.2m/s2[1]
Albedo:<0.12
Single Temperature:1537 ± 35 K

CoRoT-2b (formerly known as CoRoT-Exo-2b[2]) is the second extrasolar planet to be detected by the French-led CoRoT mission, and orbits the star CoRoT-2 at a distance of 700 light years from Earth towards the constellation Aquila. Its discovery was announced on 20 December 2007.[3] After its discovery via the transit method, its mass was confirmed via the radial velocity method.

Characteristics

The planet is a large hot Jupiter, about 1.43 times the radius of Jupiter and approximately 3.3 times as massive. Its huge size is due to the intense heating from its parent star, which causes the outer layers of its atmosphere to bloat. The extremely large radius of the planet indicates that CoRoT-2b is very hot, estimated to be around 1500 K, even hotter than would be expected given its location close to its parent star. This fact may be a sign of tidal heating due to interactions with another planet.[4] At Jupiter-like distances its radius would roughly be the same as Jupiter.[5] The complete phase curve of this planet has been observed.[6]

CoRoT-2b orbits its star approximately once every 1.7 days, and orbits the star in a prograde direction close to the star's equator.[7] Its parent star is a G-type star, a bit cooler than the Sun but more active. It is located about 800 light-years from Earth.

As of 2008, the CoRoT-2b spin-orbit angle (that is, the angle between the equator of the star and the plane of the planet orbit) was calculated by Bouchy et al. by means of the Rossiter–McLaughlin effect[8] with a value of +7.2 ± 4.5 °.[7] The spin-orbit angle was revised in 2012 to 4.0°.

External links

Notes and References

  1. Calculated using Newtonian gravity:
    styleg=GM
    R2
  2. Change in CoRoT planets names. Schneider, J.. 10 March 2009. 19 March 2009. Exoplanets. dead. https://archive.today/20100118162658/http://listes.obs.ujf-grenoble.fr/wws/arc/exoplanets/2009-03/msg00003.html. 18 January 2010.
  3. Web site: COROT surprises a year after launch . 21 December 2007.
  4. Web site: CoRoT-exo-2 c? . 21 December 2007 . 21 December 2007.
  5. Planetesimals to Brown Dwarfs: What is a Planet? . 20 August 2006 . 193–216 . Gibor Basri . 34 . Brown . 10.1146/annurev.earth.34.031405.125058 . Annu. Rev. Earth Planet. Sci. . astro-ph/0608417 . 2006AREPS..34..193B . 119338327 .
  6. 2011sptz.prop80044C . Phase Variations, Transits and Eclipses of the Misfit CoRoT-2b . Spitzer Proposal . 80044 . 2011 . Cowan, Nicolas . Deming, Drake . Gillon, Michael . Knutson, Heather . Madhusudhan, Nikku . Rauscher, Emily .
  7. Bouchy . F. . Queloz . D. . Deleuil . M. . Loeillet . B. . Hatzes . A. P. . Aigrain . S. . Alonso . R. . Auvergne . M. . Baglin . A. . Barge . P. . Benz . W. . Bordé . P. . Deeg . H. J. . De La Reza . R. . Dvorak . R. . Erikson . A. . Fridlund . M. . Gondoin . P. . Guillot . T. . Hébrard . G. . Jorda . L. . Lammer . H. . Léger . A. . Llebaria . A. . Magain . P. . Mayor . M. . Moutou . M. . M. . Pepe . F. . Ollivier . Pätzold . C. . Transiting exoplanets from the CoRoT space mission . 10.1051/0004-6361:200809433 . Astronomy and Astrophysics . 482 . 3 . L25 . 2008 . 29 . 0803.3209 . 2008A&A...482L..25B . 15766192 .
  8. Measuring accurate transit parameters . Joshua N. Winn . 2008 . 10.1017/S174392130802629X. 0807.4929 . 4 . Proceedings of the International Astronomical Union . 99–109 . 2009IAUS..253...99W. 34144676 .