HD 142022

HD 142022
Observation data
Epoch J2000      Equinox J2000
Constellation Octans
Right ascension 16h 10m 15.02895s[1]
Declination −84° 13′ 53.8108″[1]
Apparent magnitude (V) 7.70[2] + 11.19[3]
Characteristics
Spectral type G9IV-V[4] + M1V[3]
B−V color index 0.79±0.01[2]
Astrometry
Radial velocity (Rv)−9.96±0.13[1] km/s
Proper motion (μ) RA: −337.270 mas/yr[1]
Dec.: −31.386 mas/yr[1]
Parallax (π)29.1991 ± 0.0172 mas[1]
Distance111.70 ± 0.07 ly
(34.25 ± 0.02 pc)
Absolute magnitude (MV)5.02[2]
Details[5][3]
A
Mass0.972+0.036
−0.029 M☉
Radius1.028+0.011
−0.012 R☉
Luminosity0.886±0.001[6] L☉
Surface gravity (log g)4.386±0.251 cgs
Temperature5,516±31 K
Metallicity [Fe/H]0.24±0.073 dex
Rotational velocity (v sin i)2.048±0.214 km/s
Age7.667+1.704
−1.764 Gyr
B
Mass0.60±0.07 M☉
Radius0.56±0.05 R☉
Luminosity0.063±0.014 L☉
Temperature3,892±95 K
Other designations
CD−83° 202, GC 21507, GJ 9536, HD 142022, HIP 79242, SAO 258738, LTT 6382, GCRV 65757[7]
Database references
SIMBADdata

HD 142022 is a binary star[8] 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.[2] The distance to this system is 112 light-years (34 parsecs) based on parallax, but it is drifting closer to the Sun with a radial velocity of −10 km/s.[1]

The primary, designated component A, is an old,[8] Population I G-type star with a stellar classification of G9IV-V,[4] showing a spectrum with mixed traits of a main sequence and a subgiant star. It is an estimated 7.6 billion years old and is spinning with a projected rotational velocity of 2 km/s. The star has similar mass and dimensions as the Sun, but has a 55% higher metallicity.[5] It is radiating 89%[6] of the luminosity of the Sun from its photosphere at an effective temperature of 5516 K.[5]

The magnitude 11.19[3] companion has the designation LTT 6384 and appears gravitationally bound to the primary. The pair have an angular separation of 22 arcseconds, which corresponds to a projected separation of ~820 AU. The estimated semimajor axis of their orbit is 1,033 AU.[8] The secondary is a red dwarf star with a stellar classification of M1V.[3]

The primary star has a single known planetary companion, HD 142022 Ab, discovered in 2005.[8] In 2023, the inclination and true mass of HD 142022 Ab were determined via astrometry.[9]

The HD 142022 planetary system[9]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(years) 		Eccentricity Inclination Radius
b 4.51+0.91
−0.61 MJ 		2.939±0.062 5.297+0.082
−0.073 		0.506+0.071
−0.06 		71±13 or 109±13° —
  1. ^ a b c d e f 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 Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Gaidos2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Soto2018 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Eggenberger2006 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Xiao2023 was invoked but never defined (see the help page).