Gliese 317

Starbox short
name = Gliese 317
epoch = J2000.0
constell = Pyxis
ra = RA|08|40|59.21
dec = DEC|–23|27|22.6
spectral = M3.5V
appmag_v = 12.0
dist_ly = 29.9
dist_pc = 9.17
names = GJ 317, LFT 538, LHS 2037, LPM 296, LTT 3215
Simbad = GJ+317

Gliese 317 is a red dwarf star approximately 30 light-years 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.

Planetary system

Announced in 2007, a jovial planet (designated Gliese 317 b) was confirmed to orbit the star. [cite journal |url=http://fr.arxiv.org/abs/0707.2409 |title=A New Planet Around an M Dwarf: Revealing a Correlation Between Exoplanets and Stellar Mass |author= John A. Johnson, R. Paul Butler, Geoffrey W. Marcy, Debra A. Fischer, Steven S. Vogt, Jason T. Wright, Kathryn M. G. Peek |journal=ARXIV |year=2007 |volume= |pages=27 |accessdate=2007-07-07] 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. [cite arXiv | title=Extrasolar Planet Interactions | author=Rory Barnes & Richard Greenberg | eprint=0801.3226v1 |class=astro-ph |year=2008]

OrbitboxPlanet
exoplanet = b
mass = >1.2
semimajor = 0.95
period = 692.9 ± 4
eccentricity = 0.193 ± 0.06OrbitboxPlanet hypothetical
exoplanet = c
mass = 0.83
semimajor =
period = 2700
eccentricity = 0.42

See also

* HD 108874

References

External links

*
* [http://www.lpl.arizona.edu/~rory/research/xsp/dynamics/ Extrasolar Planet Interactions] by Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona