- Source: HD 154857
- HD 154857 b
- HD 154857 c
- Daftar bintang di rasi bintang Ara
- Daftar eksoplanet
- Daftar sistem multiplanet
- Daftar planet luar surya yang ditemukan pada tahun 2000–2009
- Daftar planet luar surya yang ditemukan pada tahun 2014
- HD 154857
- HD 154857 b
- HD 154857 c
- Mikko Tuomi
- Ara (constellation)
- Mu Arae
- List of stars in Ara
- Anglo-Australian Planet Search
- List of brown dwarfs
- List of exoplanets discovered in 2014
HD 154857 is a star with two exoplanetary companions in the southern constellation of Ara. It is too dim to be visible with the naked eye having an apparent visual magnitude of 7.25. The star is located at a distance of 207 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +28 km/s.
This is a G-type star with a stellar classification of G5IV-V. The absolute magnitude of this star is two magnitudes above the main sequence, which suggests that the star is evolving toward the subgiant stage. It is a metal-poor thin disk star approximately six billion years old and is chromopherically quiet although not in a Maunder Minimum state. The star is larger, more massive, and more luminous than the Sun. It is spinning with a projected rotational velocity of 1.4 km/s.
Planetary system
The discovery of one confirmed and one unconfirmed Jovian exoplanet was reported in 2004 and 2007 respectively. The former 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 additional object (HD 154857 c) was confirmed as a planetary companion in January 2014.
See also
List of extrasolar planets
References
External links
"HD 154857". Extrasolar Planets Encyclopaedia. Archived from the original on July 2, 2007. Retrieved 2008-07-21.
http://planetquest.jpl.nasa.gov