Kepler-6b is an

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detect ...

in the orbit of the unusually metal-rich

Kepler-6 Kepler-6 is a G-type star situated in the constellation Cygnus. The star lies within the field of view of the Kepler Mission, which discovered it as part of a NASA-led mission to discover Earth-like planets. The star, which is slightly ...

, a star in the field of view of the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

-operated

Kepler Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of p ...

spacecraft, which searches for planets that cross directly in front of, or

transit Transit may refer to: Arts and entertainment Film * ''Transit'' (1980 film), a 1980 Israeli film * ''Transit'' (1986 film), a Canadian short film * ''Transit'' (2005 film), a film produced by MTV and Staying-Alive about four people in countrie ...

, their host stars. It was the third planet to be discovered by Kepler. Kepler-6 orbits its host star every three days from a distance of .046 AU. Its proximity to Kepler-6 inflated the planet, about two-thirds the mass of Jupiter, to slightly larger than Jupiter's size and greatly heated its atmosphere. Follow-up observations led to the planet's confirmation, which was announced at a meeting of the

American Astronomical Society The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the adv ...

on January 4, 2010 along with four other Kepler-discovered planets.

Discovery and naming

's Kepler satellite trails the Earth and continually observes a portion of the sky between the constellations Cygnus and

Lyra , from ; pronounced: ) is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star ...

. It is devised to search for and discover planets that

, or cross in front of, their host stars with respect to Earth by measuring small and generally periodic variations in a star's brightness. Kepler recognized a potential transit event around a star that was designated

KOI , or more specifically , are colored varieties of carp ('' Cyprinus'' sp.) that are kept for decorative purposes in outdoor koi ponds or water gardens. Koi is an informal name for the colored variants of carp kept for ornamental purposes. ...

-017, which was named Kepler-6 after the confirmation of Kepler-6b. The star was designated "6" because it was the sixth planet to be observed (but the third planet to be discovered) by the Kepler satellite. After the initial detection of a transit signal by Kepler, follow-up observations were taken to confirm the planetary nature of the candidate.

Speckle imaging Speckle imaging comprises a range of high-resolution astronomical imaging techniques based on the analysis of large numbers of short exposures that freeze the variation of atmospheric turbulence. They can be divided into the shift-and-add ("' ...

by the

WIYN Telescope The WIYN Observatory is owned and operated by the WIYN Consortium. Its 3.5-meter telescope is the second largest optical telescope at Kitt Peak National Observatory in Arizona. Most of the capital costs for the observatory were provided by the U ...

was used to determine the amount of light from nearby, background stars that was present. If not accounted for, this light would have made Kepler-6 appear brighter than it actually was. Consequently, the size of Kepler-6b would have been underestimated.

Radial velocity The radial velocity or line-of-sight velocity of a target with respect to an observer is the rate of change of the vector displacement between the two points. It is formulated as the vector projection of the target-observer relative velocity ...

data was taken by

HIRES Hires may refer to: * High Resolution Fly's Eye, ultra-high-energy cosmic ray observatory * High Resolution Echelle Spectrometer or High Resolution Echelle Spectrograph, W. M. Keck Observatory's spectrometer * Hires Big H, restaurant chain headquar ...

at the

Keck I The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and, when c ...

telescope in order to determine the mass of the planet. Independently, observations were made with the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003, that was deactivated when operations ended on 30 January 2020. Spitzer was the third space telescope dedicate ...

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

wavelengths of 3.6 and 4.5 micrometres. Along with additional data taken by Kepler, these observations detected the

occultation An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks f ...

and phase curves of Kepler-6b behind its star. The confirmation of Kepler-6b was announced at the 215th meeting of the

with the discoveries of planets

Kepler-4b Kepler-4b, initially known as KOI 7.01, is an extrasolar planet first detected as a transit by the Kepler spacecraft. Its radius and mass are similar to that of Neptune; however, due to its proximity to its host star, it is substantially hotter ...

Kepler-5b __NOTOC__ Kepler-5b is one of the first five planets discovered by NASA's Kepler spacecraft. It is a hot Jupiter that orbits a subgiant star that is more massive, larger, and more diffuse than the Sun is. Kepler-5 was first flagged as the locati ...

Kepler-7b Kepler-7b is one of the first five exoplanets to be confirmed by NASA's Kepler spacecraft, and was confirmed during the first 34 days of Kepler's science operations. It orbits a star slightly hotter and significantly larger than the Sun that is e ...

, and

Kepler-8b Kepler-8b is the fifth of the first five exoplanets discovered by NASA's Kepler spacecraft, which aims to discover planets in a region of the sky between the constellations Lyra and Cygnus that transit (cross in front of) their host stars. The ...

on January 4, 2010.

Host star

Kepler-6 is a sunlike star in the Cygnus constellation. It is approximately 20.9% more massive than and 39.1% larger than the Sun. With an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 5647 K, Kepler-6 is cooler than the Sun. It is predicted to be 3.8 billion years old, compared to the Sun's age of 4.6 billion years. It is most notable for its unusually high

metallicity In astronomy, metallicity is the Abundance of the chemical elements, abundance of Chemical element, elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable (i.e. non-Dark matter, dark) matt ...

for an exoplanet-bearing star; with an e/H= 0.34, Kepler-6 has 2.18 times more iron than the Sun does. Kepler-6b is the only planet that has been discovered in the orbit of Kepler-6.

Characteristics

Kepler-6b is a

hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter (i.e. Jupiter analogue, Jupiter analogues) but that have very short orbital periods (). The close proximity to t ...

, having a mass 0.669 times that of Jupiter, but an average distance of only 0.046 AU from its star and, thus, an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 3.23 days. It is almost 10 times closer to its star than Mercury is from the Sun. As a result, Kepler-6b is strongly irradiated by its star, heating its atmosphere to a temperature of 1660 K and puffing it up to a size 1.3 times that of Jupiter. It may also be the case that Kepler-6b has a

thermal inversion In meteorology, an inversion (or temperature inversion) is a phenomenon in which a layer of warmer air overlies cooler air. Normally, air temperature gradually decreases as altitude increases, but this relationship is reversed in an inver ...

of its atmosphere, where temperature increases with increasing distance from the center of the planet. The planet is likely to be tidally locked to the parent star. In 2015, the planetary nightside temperature was estimated to be equal to 1719 K.A Comprehensive Study of Kepler Phase Curves and Secondary Eclipses:Temperatures and Albedos of Confirmed Kepler Giant Planets
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References

External links

{{Sky, 19, 47, 20.9, +, 48, 14, 23.8 Exoplanets with Kepler designations Exoplanets discovered in 2010 Hot Jupiters Giant planets Transiting exoplanets Cygnus (constellation) 6b