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HD 154857

HD 154857 is a yellow main-sequence star approximately 224 light years away in the constellation of Ara.

Planetary system

There is one confirmed and one unconfirmed planet discovered in 2004 and 2007[1] respectively. The confirmed planet HD 154857 b has mass >1.8 times that of Jupiter. It orbits the star 20% further than Earth-Sun distance, taking 409 days with 47% eccentricity. The unconfirmed planet HD 154857 c with unknown mass (probably around 18 Jupiter masses) takes at least 1900 days to orbit around the star with an orbital eccentricity exceeding 0.25.

The HD 154857 system[1]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity
b >1.8 ± 0.4 MJ 1.2 ± 0.2 409 ± 1 0.47 ± 0.02
c (unconfirmed) ≥18.4 MJ  ? >1900 ≥0.25

See also

* List of extrasolar planets


References

1. ^ a b O'Toole et al.; Butler, R. Paul; Tinney, C. G.; Jones, Hugh R. A.; Marcy, Geoffrey W.; Carter, Brad; McCarthy, Chris; Bailey, Jeremy et al. (2007). "New Planets around Three G Dwarfs". The Astrophysical Journal 660 (2): 1636–1641. doi:10.1086/513563. http://www.iop.org/EJ/article/0004-637X/660/2/1636/70956.html.

* McCarthy, Chris; Butler, R. Paul; Tinney, C. G.; Jones, Hugh R. A.; Marcy, Geoffrey W.; Carter, Brad; Penny, Alan J.; Fischer, Debra A. (2004). "Multiple Companions to HD 154857 and HD 160691". The Astrophysical Journal 617 (1): 575–579. doi:10.1086/425214. http://adsabs.harvard.edu/abs/2004ApJ...617..575M. Retrieved 2007-07-08.

* HIP 84069 - Catalog
* Image HD 154857


External links

* "HD 154857". The Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=HD+154857. Retrieved 2008-07-21.
* "HD 154857". Extrasolar Visions. http://www.extrasolar.net/planettour.asp?StarCatId=normal&StarId=226. Retrieved 2008-07-21.
* http://planetquest.jpl.nasa.gov

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