HD 82943

Starbox short
name = HD 82943
constell = Hydra
ra = RA|09|34|50.736
dec = DEC|−12|07|46.365
appmag_v = 6.54
absmag_v =
dist_ly = 89.56
dist_pc = 27.46
class = G0V
names = BD-11°2670, HIP 47007, SAO 155312
Simbad = HD+82943

HD 82943 is a yellow dwarf star approximately 89 light-years away in the constellation of Hydra. As of 2001, two extrasolar planets have been confirmed to be orbiting around the star. [cite journal | url=http://www.edpsciences.org/articles/aa/abs/2004/07/aa0250/aa0250.html |author=Mayor et al.|title=The CORALIE survey for southern extra-solar planets XII. Orbital solutions for 16 extra-solar planets discovered with CORALIE |journal = Astronomy and Astrophysics | volume=415 | year=2004 | pages=391 – 402|doi=10.1051/0004-6361:20034250|format=abstract ] [cite journal|doi= 10.1086/504701|author=Butler, R. et al.|title=Catalog of Nearby Exoplanets|journal=The Astrophysical Journal|volume=646|pages=505 – 522|year=2006 ( [http://xxx.lanl.gov/abs/astro-ph?papernum=0607493 web Preprint] )] Because of the some stellar characteristics, it is thought that the system had more giant planets that were "swallowed" by the parent star.cite web |url=http://www.eso.org/public/outreach/press-rel/pr-2001/pr-10-01.html |title=The Harsh Destiny of a Planet? |accessdate=2008-07-15 |work=European Southern Observatory |publisher= |date=2001-05-09 ]

Planetary system

The first planet discovered (designated HD 82943 b) was announced in 2000 by a team of French astronomers lead by Michel Mayor. The planet orbits its parent star at a mean distance of 1.19 astronomical units (AU) and taking approximately 441 days to complete the orbit. Nearly a year later, a second planet (designated HD 82943 c) was announced by the same discoverers of the previous planet. The planet orbits parent star in a closer orbit than the previously discovered planet (not to be confused with its designation) at a mean distance of 0.746 AU and taking 219 days to complete its orbit. [cite journal|doi= 10.1086/500566|author=Lee et al.|title=On the 2:1 Orbital Resonance in the HD 82943 Planetary System|journal=The Astrophysical Journal|volume=641|pages=1178 – 1187|year=2006 ( [http://xxx.lanl.gov/abs/astro-ph?papernum=0512551 web Preprint] )] Both planets are more massive than Jupiter, but are not massive enough to have been quoted as "Super-Jupiters."

Announced in 2001, HD 82943 was found to contain an unusually high amount of Lithium-6. Stars do not naturally contain Lithium-6, but unlike stars, planets never reach temperatures that are high enough to burn their initial content of Lithium-6 (planets should retain Lithium-6). The simplest and most convincing answer to explain this observation is that one or more planets, or at least planetary material, have fallen into the star, sometime after it passed through its early evolutionary stage.

OrbitboxPlanet
exoplanet = c
mass = 2.01
semimajor = 0.746
period = 219
eccentricity = 0.359OrbitboxPlanet
exoplanet = b
mass = 1.75
semimajor = 1.19
period = 441.2
eccentricity = 0.219

See also

* Gliese 876
* HD 169830
* Mu Arae

References

External links

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