XO-2Nb (or rarely XO-2Bb) is an

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 ...

orbiting the

star A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make ...

XO-2N, the fainter component of XO-2 wide binary star in the constellation

Lynx A lynx is a type of wild cat. Lynx may also refer to: Astronomy * Lynx (constellation) * Lynx (Chinese astronomy) * Lynx X-ray Observatory, a NASA-funded mission concept for a next-generation X-ray space observatory Places Canada * Lynx, Ontar ...

. This planet was found by 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 ...

in 2007 by Burke et al. This was the second such planet found by the

XO telescope The XO Telescope is an astronomical telescope located on the 3,054 m (10,000 foot) summit of Haleakala on Maui, Hawaii. It consists of two 200-millimeter telephoto camera lenses, and resembles binoculars in shape. It is used by the XO Proje ...

. Like most planets found by the transit method, it is a roughly

Jupiter Jupiter is the fifth planet from the Sun and the 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 slightly less than one-thousandt ...

sized planet that orbits very close to its host star; in this case, it has a surface

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on ...

of about 1200 K, so it belongs to a group of exoplanets known as

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 ...

s. The planet takes 2.6 days to orbit the star at the average distance of 0.0369 AU. The planet has mass of 57% of Jupiter and radius of 97% of Jupiter. The radius is relatively large for its mass, probably due to its intense heating from its nearby star that bloats the planet's

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. ...

. The large radius for its mass gives a low density of 820 kg/m³.

References

External links

{{Sky, 07, 48, 07, +, 50, 13, 33, 486 Lynx (constellation) Hot Jupiters Transiting exoplanets Exoplanets discovered in 2007 Giant planets

See also

References

External links