Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Scorpius |
Right ascension | 17h 50m 38.35575s [1] |
Declination | −40° 19′ 06.0723″ [1] |
Apparent magnitude (V) | 9.10 [2] |
Characteristics | |
Spectral type | K3V [3] |
B−V color index | 0.964±0.066 [2] |
Astrometry | |
Radial velocity (Rv) | −26.55±2.30 [4] km/s |
Proper motion (μ) | RA: +19.412 mas/yr [1] Dec.: −25.799 mas/yr [1] |
Parallax (π) | 31.8624 ± 0.0622 mas [1] |
Distance | 102.4 ± 0.2 ly (31.38 ± 0.06 pc) |
Absolute magnitude (MV) | 6.76 [2] |
Orbit [5] | |
Period (P) | 8.4282388+0.0000014 −0.0000026 d |
Semi-major axis (a) | 0.0859±0.0010 AU |
Eccentricity (e) | 0.28126±0.00057 |
Inclination (i) | 177.273+0.030 −0.027° |
Longitude of the node (Ω) | 288.93+0.67 −0.73° |
Periastron epoch (T) | 2457393.1874+0.0026 −0.0023 |
Argument of periastron (ω) (secondary) | 28.70+0.13 −0.12° |
Semi-amplitude (K1) (primary) | 1.8112+0.0013 −0.0016 km/s |
Details [5] | |
Mass | 0.797±0.042 M☉ |
Radius | 0.770±0.017 R☉ |
Luminosity | 0.413+0.056 −0.050 L☉ |
Surface gravity (log g) | 4.567±0.028 cgs |
Temperature | 5,270+190 −180 K |
Metallicity [Fe/H] | −0.18+0.17 −0.19 dex |
Rotational velocity (v sin i) | 1.9 [6] km/s |
Age | 5.7±4.7 Gyr [7] 3.1±2.7 [8] Gyr |
HD 162020 b | |
Mass | 0.39±0.02 [9] M☉ |
Mass | 410.8+5.8 −5.3 MJup |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
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, [2] which is too faint to be visible to the naked eye. The distance to this system is 102 light-years (31 parsecs ) based on stellar parallax. [1] It is drifting closer to the Sun with a radial velocity of −27 km/s, [4] and is predicted to come to within ~18 light-years 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]
HD 162020 b is a companion, initially thought to be a brown dwarf, with a minimum mass of 15.0 MJ. 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 0.075 AU 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 0.39 M☉ and thus likely a red dwarf star. [9] A full orbital solution was published in 2023. [5]
HD 27894 is a 9th magnitude star located approximately 143 light years away in the constellation of Reticulum. It is an orange dwarf, a type dimmer and cooler than the Sun.
HD 114729 is a Sun-like star with an orbiting exoplanet in the southern constellation of Centaurus. Based on parallax measurements, it is located at a distance of 124 light years from the Sun. It is near the lower limit of visibility to the naked eye, having an apparent visual magnitude of 6.68 The system is drifting further away with a heliocentric radial velocity of 26.3 km/s. The system has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.373″·yr−1.
HD 38529 is a binary star approximately 138 light-years away in the constellation of Orion.
HD 142 is a wide binary star system in the southern constellation of Phoenix. The main component has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.7. The system is located at a distance of 85.5 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +6 km/s.
Gliese 849, or GJ 849, is a small, solitary star in the equatorial constellation of Aquarius. It has a reddish hue and is invisible to the naked eye with an apparent visual magnitude of 10.41. The distance to this star is 28.8 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −15.3 km/s. It has a pair of confirmed gas giant companions.
HD 125612 is a binary star system with three exoplanetary companions in the equatorial constellation of Virgo. It is too dim to be visible to the naked eye, having an apparent visual magnitude of 8.31. The system is located at a distance of 188 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −18 km/s.
HD 81040 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of +7.73 it is too dim to be visible to the naked eye but can be viewed with a small telescope. The star is located at a distance of 112 light years from the Sun based on parallax. It is drifting further away with a radial velocity of +49 km/s, having come to within 48 light-years some 527,000 years ago.
HD 43691 is a star with an orbiting exoplanet in the constellation Auriga. With an apparent visual magnitude of 8.03, it is too faint to be visible to the naked eye. This system is located at a distance of 279 light years based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −29 km/s.
NGC 2423-3 is a red giant star approximately 3,040 light-years away in the constellation of Puppis. The star is part of the NGC 2423 open cluster. The star has an apparent magnitude of 10 and an absolute magnitude of zero, with a mass of 2.4 times the Sun. In 2007, it was proposed that an exoplanet orbits the star, but this is now doubtful.
HD 4113 is a dual star system in the southern constellation of Sculptor. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 7.88. The distance to this star, as estimated by parallax measurements, is 137 light years. It is receding away from the Sun with a radial velocity of +5 km/s.
HD 117207 is a star in the southern constellation Centaurus. With an apparent visual magnitude of 7.24, it is too dim to be visible to the naked eye but can be seen with a small telescope. Based upon parallax measurements, it is located at a distance of 105.4 light-years from the Sun. The star is drifting closer with a radial velocity of −17.4 km/s. It has an absolute magnitude of 4.67.
HD 142022 is a binary star system located in the southernmost constellation of Octans. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.70. The distance to this system is 112 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −10 km/s.
HD 213240 is a possible binary star system in the constellation Grus. It has an apparent visual magnitude of 6.81, which lies below the limit of visibility for normal human sight. The system is located at a distance of 133.5 light years from the Sun based on parallax. The primary has an absolute magnitude of 3.77.
HD 126614 is a trinary star system in the equatorial constellation of Virgo. The primary member, designated component A, is host to an exoplanetary companion. With an apparent visual magnitude of 8.81, it is too faint to be seen with the naked eye. The system is located at a distance of 239 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −33 km/s.
HD 86226 is a star with a pair of orbiting exoplanet companions, found in the constellation of Hydra. With an apparent visual magnitude of 7.93, it is too dim to be visible with the naked eye. The distance to this system has been determined by the parallax method, yielding a range of 149 light years. It is receding with a heliocentric radial velocity of +19.6 km/s. A survey in 2015 has ruled out the existence of any stellar companions at projected distances above 12 astronomical units.
HD 175167 is a star with an exoplanet companion in the southern constellation of Pavo. It is too faint to be visible with the naked eye at an apparent visual magnitude of 8.01. The system is located at a distance of 232 light-years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 5 km/s. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.190 arcsec yr−1.
HD 175167 b is an exoplanet orbiting HD 175167, which is a G type star within the Pavo constellation 232 light-years away from the Earth. The planet was discovered by the Magellan Planet Search Program as the astronomical object fit the Keplerian orbital model. During the observations 13 doppler velocity tests were conducted, which showed this object's mass was at least 7.8 Jovian-masses and its orbit has a high eccentricity. The exoplanet takes 3.53 years to complete a full stellar orbit.
HD 98649 is a star with an orbiting exoplanet in the southern Crater constellation. Based on parallax measurements, it is located at a distance of 137.5 light years from the Sun. The system is drifting further away with a heliocentric radial velocity of 4.3 km/s. With an apparent visual magnitude of +8.00, it is too faint to be viewed with the naked eye. The system has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.24″·yr−1.
HD 220689 is a single star in the equatorial constellation of Aquarius. It is a challenge to view with the naked eye, having an apparent visual magnitude of +7.74, but is readily viewed with a pair of binoculars. The star is located at a distance of 153 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s. A survey in 2015 has ruled out the existence of any additional stellar companions at projected distances from 26 to 305 astronomical units.
HD 106515 is a binary star in the constellation of Virgo.