HD 154857
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ara[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | 7.25[1] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G5IV-V[3] |
| B−V Template:Engvar | Script error: No such module "val".[1] |
| Variable type | Constant[4] |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[2] km/s |
| Proper motion (μ) | RA: +87.442[2] mas/yr Dec.: −55.861[2] mas/yr |
| Parallax (π) | 15.8176±0.0197 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | 3.07[3] |
| Details | |
| Mass | Script error: No such module "val".[5] Template:Solar mass |
| Radius | Script error: No such module "val".[4] Template:Solar radius |
| Luminosity | Script error: No such module "val".[4] Template:Solar luminosity |
| Surface gravity (log g) | Script error: No such module "val".[4] cgs |
| Temperature | Script error: No such module "val".[4] K |
| Metallicity [Fe/H] | Script error: No such module "val".[6] dex |
| Rotational velocity (v sin i) | Script error: No such module "val".[7] km/s |
| Age | Script error: No such module "val".[4] Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[8] | |
| Database references | |
| SIMBAD | data |
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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.[1] The star is located at a distance of 206 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +28 km/s.[2]
This is a G-type star with a stellar classification of G5IV-V.[3] The absolute magnitude of this star is two magnitudes above the main sequence, which suggests that the star is evolving toward the subgiant stage.[3] It is a metal-poor thin disk star[9] approximately six billion years old and is chromopherically quiet although not in a Maunder Minimum state.[4] 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.[7]
Planetary system
The discovery of one confirmed and one unconfirmed Jovian exoplanet was reported in 2004[3] and 2007[10] 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.[5]
Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:OrbitboxPlanet
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See also
References
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- ↑ a b c d Template:Cite XHIP
- ↑ a b c d e f g h Template:Cite Gaia DR3
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- ↑ a b Script error: No such module "Citation/CS1".
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- ↑ a b Script error: No such module "Citation/CS1".
- ↑ Template:Cite simbad
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- ↑ Script error: No such module "Citation/CS1".
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External links
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- http://planetquest.jpl.nasa.gov