HAT-P-11
Encyclopedia
HAT-P-11, also designated GSC 03561-02092, is an orange dwarf
Orange dwarf
A K-type main-sequence star , also referred to orange dwarf, are main-sequence stars of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars and yellow G-type main-sequence stars...

 metal rich
Metallicity
In astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium...

 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...

 about 123 light-years 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....

 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...

. This star is notable for its relatively large rate of proper motion
Proper motion
The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...

. The 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...

 of this star is about 9, which means it is not visible to the naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...

 but can be seen with a medium sized amateur telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

 on a clear dark night. The age of this star is about 6.5 billion years.

Planetary system

This star has one known extrasolar planet
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...

, HAT-P-11b
HAT-P-11b
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....

, discovered by the HATNet Project
HATNet Project
The Hungarian Automated Telescope Network project is a network of six small fully automated "HAT" telescopes. The scientific goal of the project is to detect and characterize extrasolar planets using the transit method. This network is used also to find and follow bright variable stars...

 using the transit method. This planet is a little larger than Neptune. This star system is within the field of view of the now-operational Kepler Mission
Kepler Mission
The Kepler spacecraft is an American space observatory, the space-based portion of NASA's Kepler Mission to discover Earth-like planets orbiting other stars. The spacecraft is named in honor of the 17th-century German astronomer Johannes Kepler...

 planet-hunter spacecraft
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

.
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