CoRoT-2b (formerly known as CoRoT-Exo-2b) is the second

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

to be detected by the French-led

CoRoT CoRoT (French: ; English: Convection, Rotation and planetary Transits) was a space telescope mission which operated from 2006 to 2013. The mission's two objectives were to search for extrasolar planets with short orbital periods, particularly th ...

mission, and orbits the star CoRoT-2 at a distance of 700

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

towards the constellation Aquila. Its discovery was announced on 20 December 2007. After its discovery via the

transit method Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty o ...

, its mass was confirmed via the radial velocity method.

Characteristics

The planet is a large

hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere temp ...

, about 1.43 times the radius of

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

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 Tidal heating (also known as tidal working or tidal flexing) occurs through the tidal friction processes: orbital and rotational energy is dissipated as heat in either (or both) the surface ocean or interior of a planet or satellite. When an object ...

due to interactions with another planet. At Jupiter-like distances its radius would roughly be the same as Jupiter. The complete phase curve of this planet has been observed. 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 The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...

. Its parent star is a G-type star, a bit cooler than the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

but more

active Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * ''Active'' (ship), several commercial ships by that name * HMS ''Active'', the name of various ships of the British Royal ...

. It is located about 800

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from Earth. As of 2008, the CoRoT-2b spin-orbit angle (that is, the angle between the

of the star and the plane of the planet

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...

) was calculated by Bouchy ''et al.'' by means of the

Rossiter–McLaughlin effect The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when an object moves across the face of a star. Description The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when either an eclipsing binary's second ...

with a value of +7.2 ± 4.5 degrees. The spin-orbit angle was revised in 2012 to 4.0°.

References

External links

COROT-Exo-2 light curve using differential photometry
{{DEFAULTSORT:Corot-2b Hot Jupiters Transiting exoplanets Giant planets Exoplanets discovered in 2007 2b Aquila (constellation)