HD 170469

HD 170469
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 18h 29m 10.98124s[1]
Declination +11° 41′ 43.7985″[1]
Apparent magnitude (V) 8.21[2]
Characteristics
Spectral type G5V + K5V[3]
B−V color index 0.677±0.014[2]
Astrometry
Radial velocity (Rv)−59.32±0.10[3] km/s
Proper motion (μ) RA: −48.418±0.070[1] mas/yr
Dec.: −17.470±0.079[1] mas/yr
Parallax (π)16.5886 ± 0.0408 mas[1]
Distance196.6 ± 0.5 ly
(60.3 ± 0.1 pc)
Absolute magnitude (MV)4.23[2]
Orbit[4]
PrimaryHD 170469
CompanionHD 170469 B
Period (P)114000 yr
Semi-major axis (a)43.1″
Details
A
Mass1.10[5] M☉
Radius1.24[5] R☉
Luminosity1.639±0.006[1] L☉
Surface gravity (log g)4.30±0.03[5] cgs
Temperature5,786±28[3] K
Metallicity [Fe/H]0.28±0.02[3] dex
Age4.8+3.0
−0.5[2] or 8.6±0.5[6] Gyr
B
Mass0.42[7] M☉
Other designations
t2 Car, BD+11º3479, Gaia DR2 4484013343859055744, HD 170469, HIP 90593, SAO 103765, 2MASS J18291097+1141437[8]
Database references
SIMBADdata

HD 170469 is a probable binary star[7][4] system in the equatorial constellation of Ophiuchus. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.21.[2] The system is located at a distance of 197 light years away from the Sun based on parallax. It is drifting closer with a radial velocity of −59 km/s,[3] and is expected to come to within 49.8 light-years in about 959,000 years.

The primary, component A, is a G-type main-sequence star with a stellar classification of G5V,[3] indicating it is generating energy through core hydrogen fusion. Estimates of the star's age range from five[2] to almost nine[6] billion years. It has 1.10 times the mass of the Sun and 1.24 times the Sun's radius.[5] The star has a higher than solar metallicity.[3] It is radiating 1.64[1] times the Sun's luminosity from its photosphere at an effective temperature of 5,786 K.[3]

The secondary companion, component B, is located at an angular separation of 43.21″±0.10″ along a position angle of 112.55°±0.07° from the primary, as of 2018.[3] Initially it was thought to be a red dwarf of spectral class M1,[4] but was later determined to be a K-type main-sequence star with a class of K5V.[3] This star lies at a projected separation of 2708 AU[4] from the primary, and is orbiting with an estimated period of around 114,000 years.[7]

Planetary system

In 2007, a planet was discovered by the N2K Consortium, led by principal investigators Debra Fischer and Gregory P. Laughlin.[9] It was spotted using the radial velocity method, and was independently confirmed in 2014.[4]

The HD 170469 planetary system[9]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b >0.67 MJ 2.24 1,143 0.11 — —

See also

References

  1. ^ a b c d e f g Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  3. ^ a b c d e f g h i j Montes, D.; et al. (September 2018). "Calibrating the metallicity of M dwarfs in wide physical binaries with F-, G-, and K-primaries - I: High-resolution spectroscopy with HERMES: stellar parameters, abundances, and kinematics". Monthly Notices of the Royal Astronomical Society. 479 (1): 1332–1382. arXiv:1805.05394. Bibcode:2018MNRAS.479.1332M. doi:10.1093/mnras/sty1295. S2CID 119260219.
  4. ^ a b c d e Mugrauer, M.; et al. (March 2014). "New wide stellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 439 (1): 1063–1070. Bibcode:2014MNRAS.439.1063M. doi:10.1093/mnras/stu044.
  5. ^ a b c d Stassun, Keivan G.; et al. (2017). "Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes". The Astronomical Journal. 153 (3): 136. arXiv:1609.04389. Bibcode:2017AJ....153..136S. doi:10.3847/1538-3881/aa5df3. S2CID 119219062.
  6. ^ a b Bonfanti, A.; et al. (March 2015). "Revising the ages of planet-hosting stars". Astronomy & Astrophysics. 575: 17. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. S2CID 54555839. A18.
  7. ^ a b c Tokovinin, Andrei (2014). "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 87. arXiv:1401.6827. Bibcode:2014AJ....147...87T. doi:10.1088/0004-6256/147/4/87. S2CID 56066740.
  8. ^ "HD 170469". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-13.
  9. ^ a b Fischer, Debra A.; et al. (2007). "Five Intermediate-Period Planets from the N2K Sample". The Astrophysical Journal. 669 (2): 1336–1344. arXiv:0704.1191. Bibcode:2007ApJ...669.1336F. doi:10.1086/521869. S2CID 7774321.