HD 164922
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hercules[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | +6.99[3] |
| Characteristics | |
| Spectral type | G9V[4] |
| B−V Template:Engvar | Script error: No such module "val".[3] |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[2] km/s |
| Proper motion (μ) | RA: 389.772 mas/yr[2] Dec.: -602.431 mas/yr[2] |
| Parallax (π) | 45.4954±0.0167 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | 5.29[1] |
| Details | |
| Mass | 0.874 ± 0.012[4] Template:Solar mass |
| Radius | 0.999 ± 0.017[4] Template:Solar radius |
| Luminosity | 0.703 ± 0.017[4] Template:Solar luminosity |
| Surface gravity (log g) | 4.387 ± 0.014[4] cgs |
| Temperature | Script error: No such module "val".[3] K |
| Metallicity [Fe/H] | 0.16 ± 0.05[4] dex |
| Rotation | Script error: No such module "val".[3] |
| Rotational velocity (v sin i) | <2.0[3] km/s |
| Age | 13.4,[5] Script error: No such module "val".[3] Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| BD +26°3151, GJ 700.2, LFT 1388, SAO 85678, HIP 88348, 2MASS J18023085+2618471 | |
| Database references | |
| SIMBAD | data |
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HD 164922 is a seventh magnitude G-type main sequence star in the constellation of Hercules. To view it, binoculars or a telescope are necessary, as it is too faint to be visible to the naked eye. It is Script error: No such module "convert". distant from the Earth. It is reaching the end of its main sequence life and will soon evolve to become a red giant.[2]
Nomenclature
The name HD 164922 derives directly from the fact that the star is the 164,922nd star listed in the Henry Draper catalog. The designation b for its planet derives from the order of discovery. The designation of b is given to the first planet found orbiting a given star, followed by the other lowercase letters of the alphabet.[6] In the case of HD 164922, only one was discovered, which was designated b, followed by three more planets, which were designated c, d, and e.[4][7]
Stellar characteristics
HD 164922 is a G-type main sequence star that is approximately 87% the mass of and 99% the radius of the Sun. It has a temperature of 5390 K and is about 10 billion years old,[3] with estimates ranging as high as 13.4 billion years.[5] In comparison, the Sun is about 4.6 billion years old[8] and has a temperature of 5778 K.[9]
The star is metal-rich, with a metallicity ([Fe/H]) of 0.16, or 144% the solar amount. This is particularly odd for a star as old as HD 164922. Its luminosity (Template:Solar luminosity) is 70% of the solar luminosity.[4]
Planetary system
On 15 July 2006, a long period Saturn-mass exoplanet was announced orbiting around HD 164922. This planet orbits at 2.11 AU from the star with a low eccentricity value of 0.05.[10]
Almost exactly ten years later in 2016, another exoplanet, though less massive than the first planet, was discovered orbiting farther in from the star. This planet has a minimum mass of nearly 13 times that of Earth, meaning it is possibly a Neptune-like planet.[4]
A third exoplanet, a hot super-Earth, was discovered in 2020,[3] and a fourth, Neptune-mass, in 2021.[7] Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:OrbitboxPlanet Template:OrbitboxPlanet Template:OrbitboxPlanet
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See also
- List of exoplanets discovered between 2000–2009 - HD 164922 b
- List of exoplanets discovered in 2016 - HD 164922 c
- List of exoplanets discovered in 2020 - HD 164922 d
- List of exoplanets discovered in 2021 - HD 164922 e
References
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- ↑ a b c d e f Template:Cite Gaia DR3
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- ↑ a b Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ a b Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
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- ↑ Script error: No such module "Citation/CS1".
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External links
- The Extrasolar Planet Encyclopedia: HD 164922
- SIMBAD: HD 164922
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