HAT-P-11b
Encyclopedia
HAT-P-11b is an extrasolar planet
orbiting the star HAT-P-11
. This planet was discovered by the transit method and submitted for publication on January 2, 2009.
This planet is located approximately 123 ly away in the constellation
of Cygnus
, orbiting the 10th magnitude
K-type star
HAT-P-11
. This planet was the smallest transiting planet known when first discovered, with a radius about 5 times that of Earth; but is more massive than Gliese 436 b
at a true mass
of 26 times that of Earth
. This planet orbits about the same distance from the star as 51 Pegasi b
is from 51 Pegasi
, typical of transiting planets. However, the orbit of this planet is eccentric, at around 0.198, unusually high for this hot Neptune
. HAT-P-11b's orbit is also highly inclined, with a tilt of approximately 103 degrees relative to its star's rotation.
The HAT-P-11 system is within the field of view
of the now operational Kepler spacecraft.
Its radial velocity is drifting and this may be a result of an as-yet-undiscovered planet in the system.
The planet fits models for 90% heavy elements. Expected temperature is 878 ± 15K. Actual temperature must await calculations of secondary transit.
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
orbiting the star HAT-P-11
HAT-P-11
HAT-P-11, also designated GSC 03561-02092, is an orange dwarf metal rich star about 123 light-years away in the constellation Cygnus. This star is notable for its relatively large rate of proper motion. The magnitude of this star is about 9, which means it is not visible to the naked eye but can be...
. This planet was discovered by the transit method and submitted for publication on January 2, 2009.
This planet is located approximately 123 ly away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Cygnus
Cygnus (constellation)
Cygnus is a northern constellation lying on the plane of the Milky Way. Its name is the Latinized Hellenic word for swan. One of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross...
, orbiting the 10th magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
K-type star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
HAT-P-11
HAT-P-11
HAT-P-11, also designated GSC 03561-02092, is an orange dwarf metal rich star about 123 light-years away in the constellation Cygnus. This star is notable for its relatively large rate of proper motion. The magnitude of this star is about 9, which means it is not visible to the naked eye but can be...
. This planet was the smallest transiting planet known when first discovered, with a radius about 5 times that of Earth; but is more massive than Gliese 436 b
Gliese 436 b
Gliese 436 b is a Neptune-sized extrasolar planet orbiting the red dwarf star Gliese 436. It was among the smallest known transiting planets in mass and radius until the much smaller Kepler discoveries started coming in 2010.-Discovery:...
at a true mass
True mass
The term true mass is synonymous with the term mass, but is used in astronomy to differentiate the measured mass of a planet from the lower limit of mass usually obtained from radial velocity techniques...
of 26 times that of Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. This planet orbits about the same distance from the star as 51 Pegasi b
51 Pegasi b
51 Pegasi b , sometimes though unofficially named Bellerophon, is an extrasolar planet approximately 50 light-years away in the constellation of Pegasus...
is from 51 Pegasi
51 Pegasi
51 Pegasi is a Sun-like star located 15.6 parsecs from Earth in the constellation Pegasus...
, typical of transiting planets. However, the orbit of this planet is eccentric, at around 0.198, unusually high for this hot Neptune
Hot Neptune
A hot Neptune is an extrasolar planet in an orbit close to its star , with a mass similar to that of Uranus or Neptune. Recent observations have revealed a larger potential population of hot Neptunes than previously thought...
. HAT-P-11b's orbit is also highly inclined, with a tilt of approximately 103 degrees relative to its star's rotation.
The HAT-P-11 system is within the field of view
Field of view
The field of view is the extent of the observable world that is seen at any given moment....
of the now operational Kepler spacecraft.
Its radial velocity is drifting and this may be a result of an as-yet-undiscovered planet in the system.
The planet fits models for 90% heavy elements. Expected temperature is 878 ± 15K. Actual temperature must await calculations of secondary transit.