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HD 208487

HD 208487 is a 7th magnitude G-type main sequence star located approximately 144 light-years away in the constellation of Grus. It has the same spectral type as our sun, G2V. However, it is probably slightly less massive and more luminous, indicating that it is slightly older. As of 2008, there is one known extrasolar planet confirmed to be orbiting the star.

Planetary system

There is one known planet orbiting the star HD 208487, which is designated HD 208487 b.[1] It has a mass at least half that of Jupiter and is located in an eccentric 130-day orbit.

The discovery of a second planet in the system was announced on September 13, 2005, by P.C. Gregory. The discovery was made using Bayesian analysis of the radial velocity dataset to determine the planetary parameters.[2] However, further analysis revealed that an alternative 2-planet solution for the HD 208487 system was possible, with a planet in a 28-day orbit instead of the 908-day orbit postulated, and it was concluded that activity on the star is more likely to be responsible for the residuals to the one-planet solution than the presence of a second planet.[3]

The HD 208487 system
(in order from star)
Mass Semimajor axis
Orbital period
b >0.520 ± 0.082 MJ 0.51 ± 0.02 130.08 ± 0.51 0.24 ± 0.16

See also

* List of extrasolar planets


1. ^ Tinney et al.; Butler, R. Paul; Marcy, Geoffrey W.; Jones, Hugh R. A.; Penny, Alan J.; McCarthy, Chris; Carter, Brad D.; Fischer, Debra A. (2005). "Three Low-Mass Planets from the Anglo-Australian Planet Search". The Astrophysical Journal 623 (2): 1171–1179. doi:10.1086/428661. http://www.iop.org/EJ/article/0004-637X/623/2/1171/61345.html.
2. ^ Gregory, P.C. (2006). "A Bayesian Kepler periodogram detects a second planet in HD 208487". MNRAS 374 (4): 1321–1333. doi:10.1111/j.1365-2966.2006.11240.x. Bibcode: 2007MNRAS.374.1321G.
3. ^ Wright, J.T. et al. (2007). "Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars". The Astrophysical Journal 657 (1): 533–545. doi:10.1086/510553. Bibcode: 2007ApJ...657..533W. http://www.iop.org/EJ/article/0004-637X/657/1/533/65907.html.

* Butler et al.; Wright, J. T.; Marcy, G. W.; Fischer, D. A.; Vogt, S. S.; Tinney, C. G.; Jones, H. R. A.; Carter, B. D. et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646 (1): 505–522. doi:10.1086/504701. http://www.iop.org/EJ/article/0004-637X/646/1/505/64046.html.

External links

* "Notes for star HD 208487". The Extrasolar Planets Encyclopaedia. http://exoplanet.eu/star.php?st=HD+208487. Retrieved 2008-08-29.
* "HD 208487". Extrasolar Visions. http://www.extrasolar.net/planettour.asp?StarCatId=normal&StarId=. Retrieved 2008-08-29.

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