Gliese 317
Encyclopedia
Gliese 317 is a red dwarf
star approximately 50 light-year
s away in the constellation
of Pyxis
. The star has an apparent magnitude
of 12, an absolute magnitude
of 12.2, and corresponding to visual luminosity
of 0.1% Sun
. As of 2007, at least one extrasolar planet
has been confirmed to be orbiting the star.
) was confirmed to orbit the star. The planet orbits about 95% the distance
between Earth to the Sun
. Despite of this, it takes about 1.9 years, corresponding to slow orbital velocity
of 14.82 km/s.
There is a possible second planet in the system; if it exists, the orbital parameters would change for the first planet. It would have an orbital period
of 673.4 days and eccentricity of 0.25. A stability analysis on this putative system constrained its orbits to a 4:1 mean motion resonance
.
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....
star approximately 50 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s 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 Pyxis
Pyxis
Pyxis is a small and faint constellation in the southern sky. Its name is Latin for a mariner's compass...
. The star has an apparent 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 12, an absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
of 12.2, and corresponding to visual luminosity
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
of 0.1% 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...
. As of 2007, at least one 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...
has been confirmed to be orbiting the star.
Planetary system
Announced in 2007, a jovian planet (designated Gliese 317 bGliese 317 b
Gliese 317 b is an extrasolar planet approximately 50 light-years away in the constellation of Pyxis. The planet was announced in July 2007 to be orbiting the red dwarf star Gliese 317. The planet is a jovian planet that orbits about 95% the distance between Earth to the Sun. Despite of this, it...
) was confirmed to orbit the star. The planet orbits about 95% the distance
Distance
Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, or an estimation based on other criteria . In mathematics, a distance function or metric is a generalization of the concept of physical distance...
between Earth to 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...
. Despite of this, it takes about 1.9 years, corresponding to slow orbital velocity
Orbital velocity
Orbital velocity can refer to the following:* The orbital speed of a body in a gravitational field.* The velocity of particles due to wave motion, in particular in wind waves....
of 14.82 km/s.
There is a possible second planet in the system; if it exists, the orbital parameters would change for the first planet. It would have an orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of 673.4 days and eccentricity of 0.25. A stability analysis on this putative system constrained its orbits to a 4:1 mean motion resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
.