Kepler-16
Encyclopedia
Kepler-16 is a binary star
system in the constellation
of Cygnus
that was targeted by the Kepler spacecraft. Both stars are smaller than the Sun
; the primary, Kepler-16A, is a class K red dwarf, and the secondary, Kepler-16B, is a class M red dwarf
. They are separated by 0.22 AU
, and complete an orbit around a common center of mass every 41 days.
The system is host to one known extrasolar planet
in circumbinary orbit
: the Saturn
-sized Kepler-16b
.
that orbits the two stars in the Kepler-16 system. The planet is a third of Jupiter's mass
and slightly smaller than Saturn at 0.7538 Jupiter radii, but is more dense. Kepler-16b completes a nearly circular orbit every 228.776 days.
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
system 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...
that was targeted by the Kepler spacecraft. Both stars are smaller than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
; the primary, Kepler-16A, is a class K red dwarf, and the secondary, Kepler-16B, is a class M red dwarf
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
. They are separated by 0.22 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
, and complete an orbit around a common center of mass every 41 days.
The system is host to 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...
in circumbinary orbit
Circumbinary planet
A circumbinary planet is a planet that orbits two stars instead of one.Because of the close proximity and orbit of some binary stars, the only way for planets to form is by forming outside the orbit of the two stars....
: the Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
-sized Kepler-16b
Kepler-16b
Kepler-16b is an extrasolar planet. It is a Saturn-mass planet consisting of half rock and half gas, and it orbits a binary star, Kepler-16, with a period of 229 days...
.
Planetary system
Kepler-16b is a gas giantGas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
that orbits the two stars in the Kepler-16 system. The planet is a third of Jupiter's mass
Jupiter mass
Jupiter mass , is the unit of mass equal to the total mass of the planet Jupiter . Jupiter mass is used to describe masses of the gas giants, such as the outer planets and extrasolar planets. It is also used in describing brown dwarfs....
and slightly smaller than Saturn at 0.7538 Jupiter radii, but is more dense. Kepler-16b completes a nearly circular orbit every 228.776 days.
Further reading
- Spin-Orbit Alignment for the Circumbinary Planet Host Kepler-16A , Joshua N. Winn et al. 2011