HD 162020
Star in the constellation Scorpius / From Wikipedia, the free encyclopedia
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]
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 |
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]