HD 154857
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ara |
| Right ascension | 17h 11m 15.7219s |
| Declination | -56° 40′ 50.865″ |
| Apparent magnitude (V) | 7.25 |
| Characteristics | |
| Spectral type | G5V |
| B−V color index | 0.699 ± 0.001 |
| Astrometry | |
| Radial velocity (Rv) | 27.9 ± 0.2 km/s |
| Proper motion (μ) | RA: 87.19 ± 0.8 mas/yr Dec.: -55.37 ± 0.57 mas/yr |
| Parallax (π) | 14.59 ± 0.91 mas |
| Distance | 220 ± 10 ly (69 ± 4 pc) |
| Absolute magnitude (MV) | 7.9 |
| Details | |
| Mass | 1.17 (± 0.05) M☉ |
| Radius | 2.42 R☉ |
| Luminosity | 0,679381 L☉ |
| Surface gravity (log g) | 5,579844548 g cgs |
| Temperature | 5445 K |
| Metallicity | -0.23 (± 0.03) % |
| Age | 8.98 G years |
| Equatorial [ g ] | 54,7 m/s2 |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) | |
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 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 takes at least 1900 days to orbit around the star with an orbital eccentricity exceeding 0.25.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >1.8±0.4 MJ | 1.2±0.2 | 409±1 | 0.47±0.02 | — | — |
| c (unconfirmed) | — | — | >1900 | >0.25 | — | — |
See also
References
- 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. Retrieved 2007-07-08.
{{cite journal}}: More than one of|work=and|journal=specified (help)CS1 maint: multiple names: authors list (link) - O'Toole; et al. (2007). "New Planets around Three G Dwarfs". The Astrophysical Journal. 660 (2): 1636–1641. doi:10.1086/513563.
{{cite journal}}: Explicit use of et al. in:|author=(help) (web Preprint)
- HIP 84069 - Catalog
- Image HD 154857
External links
- "HD 154857". The Extrasolar Planets Encyclopaedia. Retrieved 2008-07-21.
- "HD 154857". Extrasolar Visions. Retrieved 2008-07-21.
- http://planetquest.jpl.nasa.gov
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