HD 165189 and HD 165190

HD 165189
Observation data
Epoch J2000      Equinox J2000
Constellation Corona Australis
HD 165189
Right ascension 18h 06m 49.89293s[1]
Declination −43° 25′ 30.8009″[1]
Apparent magnitude (V) 5.62±0.01[2]
HD 165190
Right ascension 18h 06m 49.91494s[3]
Declination −43° 25′ 29.0976″[3]
Apparent magnitude (V) 5.68±0.01[2]
Characteristics
HD 165189
Spectral type A6 V[4]
B−V color index +0.230[5]
HD 165190
Spectral type A7 V[4]
B−V color index +0.262[5]
Astrometry
Radial velocity (Rv)−7.8±0.4[6] km/s
Absolute magnitude (MV)+1.81[7]
HD 165189
Proper motion (μ) RA: +10.915 mas/yr[1]
Dec.: −105.835 mas/yr[1]
Parallax (π)22.7417 ± 0.1025 mas[1]
Distance143.4 ± 0.6 ly
(44.0 ± 0.2 pc)
HD 165190
Proper motion (μ) RA: −1.187 mas/yr[3]
Dec.: −101.243 mas/yr[3]
Parallax (π)22.6753 ± 0.071 mas[3]
Distance143.8 ± 0.5 ly
(44.1 ± 0.1 pc)
Orbit[8][9]
Period (P)607±245 yr
Semi-major axis (a)4.63±1.83″
Eccentricity (e)0.896±0.068
Inclination (i)104±6°
Longitude of the node (Ω)84.2±5.5°
Periastron epoch (T)1854.7
Argument of periastron (ω)
(secondary)		282±9°
Details
HD 165189
Mass1.59[10] M☉
Radius1.7[1] R☉
Luminosity8.6[1] L☉
Surface gravity (log g)4.25[11] cgs
Temperature7,600[1] K
Metallicity [Fe/H]−0.25[11] dex
Rotational velocity (v sin i)130±1[12] km/s
HD 165190
Mass1.58[10] M☉
Radius1.7[3] R☉
Luminosity8.2[3] L☉
Surface gravity (log g)4.15[11] cgs
Temperature7,566[3] K
Metallicity [Fe/H]−0.24[11] dex
Rotational velocity (v sin i)129±1[12] km/s
Age813[3] Myr
Other designations
1 G. Coroane Australis, CD−43°12272, GC 24649, HIP 88726, CCDM J18068-4325, WDS J18068-4325[13]
HD 165189: HR 6749
HD 165190: HR 6750
Database references
SIMBADdata
HD 165189
HD 165190

HD 165189 and HD 165190 are components of a visual binary star[10] system located 143 light years away in the southern constellation of Corona Australis. It is visible to the naked eye with the primary having an apparent visual magnitude of 4.929±0.025. The system is a member of the Beta Pictoris Moving Group.[14]

The pair orbit each other with a period of 450 years and a large eccentricity of 0.650.[9] They have a projected separation of 70.1 AU.[10] Both components are A-type main-sequence stars; the primary has a stellar classification of A6 V while the secondary is A7 V.[14] They have similar masses of 1.59 and 1.58 times the mass of the Sun, respectively.[10]

  1. ^ a b c d e f g Cite error: The named reference GaiaDR3A was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference GaiaDR3B was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Corbally1984 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference myers2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Izmailov2019 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Alzner2001 was invoked but never defined (see the help page).
  10. ^ a b c d e Cite error: The named reference Tokovinin2016 was invoked but never defined (see the help page).
  11. ^ a b c d Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Díaz2011 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ a b Cite error: The named reference Bell2015 was invoked but never defined (see the help page).