HD 162020

HD 162020
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]
Distance102.4 ± 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]
Mass0.797±0.042 M☉
Radius0.770±0.017 R☉
Luminosity0.413+0.056
−0.050 L☉
Surface gravity (log g)4.567±0.028 cgs
Temperature5,270+190
−180 K
Metallicity [Fe/H]−0.18+0.17
−0.19 dex
Rotational velocity (v sin i)1.9[6] km/s
Age5.7±4.7 Gyr[7]
3.1±2.7[8] Gyr
HD 162020 b
Mass0.39±0.02[9] M☉
Mass410.8+5.8
−5.3 MJup
Other designations
CD−40°11894, HD 162020, HIP 87330, PPM 763039[10]
Database references
SIMBADdata
Exoplanet Archivedata

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]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Torres_et_al_2006 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Unger2023 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Udry2002 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference DelgadoMena_et_al_2019 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Bonfanti_et_al_2016 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference GaiaDR3Exoplanets was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Simbad was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference BailerJones_et_al_2018 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Poppenhaeger_Schmitt_2011 was invoked but never defined (see the help page).