HD 162020
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | 9.10[1] |
| Characteristics | |
| Spectral type | K3V[3] |
| B−V Template:Engvar | Script error: No such module "val".[1] |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[4] km/s |
| Proper motion (μ) | RA: +19.412 mas/yr[2] Dec.: −25.799 mas/yr[2] |
| Parallax (π) | 31.8624±0.0622 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | 6.76[1] |
| Orbit[5] | |
| Period (P) | Script error: No such module "val". |
| Semi-major axis (a) | Script error: No such module "val". |
| Eccentricity (e) | Script error: No such module "val". |
| Inclination (i) | Script error: No such module "val".° |
| Longitude of the node (Ω) | Script error: No such module "val".° |
| Periastron epoch (T) | Script error: No such module "val". |
| Argument of periastron (ω) (secondary) | Script error: No such module "val".° |
| Semi-amplitude (K1) (primary) | Script error: No such module "val". km/s |
| Details[5] | |
| Mass | Script error: No such module "val". Template:Solar mass |
| Radius | Script error: No such module "val". Template:Solar radius |
| Luminosity | Script error: No such module "val". Template:Solar luminosity |
| Surface gravity (log g) | Script error: No such module "val". cgs |
| Temperature | Script error: No such module "val". K |
| Metallicity [Fe/H] | Script error: No such module "val". dex |
| Rotational velocity (v sin i) | 1.9[6] km/s |
| Age | Script error: No such module "val". Gyr[7] Script error: No such module "val".[8] Gyr |
| HD 162020 b | |
| Mass | Script error: No such module "val".[9] Template:Solar mass |
| Mass | Script error: No such module "val". MJup |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[10] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
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HD 162020 is a star in the southern constellation of Scorpius with a likely red dwarf companion. It has an apparent visual magnitude of 9.10,[1] which is too faint to be visible to the naked eye. The distance to this system is Script error: No such module "convert". based on stellar parallax.[2] It is drifting closer to the Sun with a radial velocity of −27 km/s,[4] and is predicted to come to within ~Script error: No such module "convert". in 1.1 million years.[11]
This is an ordinary K-type main-sequence star with a stellar classification of K3V.[3] The age estimate is poorly constrained but it appears to have an intermediate age of several billion years. However, the activity level suggests a younger star; the rotation rate of the star may have been increased through synchronization with the companion, resulting in a higher than normal activity for its age.[6] X-ray emission has been detected from this star.[12]
HD 162020 has 74%[7] of the mass of the Sun and 73%[4] of the Sun's radius. The abundance of iron is roughly the same as the Sun, suggesting a similar metallicity. It is radiating just 25.8% of the luminosity of the Sun from its photosphere at an effective temperature of 4,801 K.[4] The star is spinning with a projected rotational velocity of 1.9 km/s.[6]
Companion
HD 162020 b is a companion, initially thought to be a brown dwarf, with a minimum mass of Template:Jupiter mass. At the time of discovery, the actual mass was undetermined since the orbital inclination was not known. This object orbits very close to the star at a distance of Script error: No such module "val". with an eccentricity (ovalness) of 0.277. The object's distance from the star ranges from 0.054 to 0.096 AU. It has an extremely high semi-amplitude of 1,813 m/s. The discovery was announced on April 15, 2000 by the Geneva Extrasolar Planet Search Team.[13][6]
Despite the presence of this massive object in an eccentric orbit around the star, computer modelling done in 2017 (when the object was still thought to be a brown dwarf) showed it is still theoretically possible for an Earth-mass exoplanet to be occupying a dynamically-stable orbit in the habitable zone of this star.[14]
An astrometric measurement of this object's true mass was published in 2022 as part of Gaia DR3, revealing it to be Template:Solar mass and thus likely a red dwarf star.[9] A full orbital solution was published in 2023.[5]
References
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- ↑ a b c d e Template:Cite Gaia DR3
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- ↑ a b c d Template:Cite Gaia DR2
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- ↑ Template:Cite simbad
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External links
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