HD 208487

HD 208487
Observation data
Epoch J2000      Equinox J2000
Constellation Grus
Right ascension 21h 57m 19.8477s
Declination −37° 45′ 49.037″
Apparent magnitude (V) 7.48
Absolute magnitude (V)4.25
Distance144.4 ly
(44.30 pc)
Spectral typeG2V:
Other designations
CD-38°14804, HIP 108375, SAO 213432
Database references
SIMBADdata

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 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b >0.520 ± 0.082 MJ 0.51 ± 0.02 130.08 ± 0.51 0.24 ± 0.16 — —

See also

References

  1. ↑ Tinney, C. G.; et al. (2005). "Three Low-Mass Planets from the Anglo-Australian Planet Search". The Astrophysical Journal. 623 (2): 1171–1179. Bibcode:2005ApJ...623.1171T. doi:10.1086/428661.
  2. ↑ Gregory, P.C. (2006). "A Bayesian Kepler periodogram detects a second planet in HD 208487". MNRAS. 374 (4): 1321–1333. arXiv:astro-ph/0609229Freely accessible. Bibcode:2007MNRAS.374.1321G. doi:10.1111/j.1365-2966.2006.11240.x.
  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. arXiv:astro-ph/0611658Freely accessible. Bibcode:2007ApJ...657..533W. doi:10.1086/510553.

Coordinates: 21h 57m 19.8477s, −37° 45′ 49.037″


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