HD 176051 is a spectroscopic binary star system[9] approximately 49 light years away from Earth in the constellation Lyra. The pair orbit with a period of 22,423 days (61.4 years) and an eccentricity of 0.25.[6] Compared to the Sun, they have a somewhat lower proportion of elements more massive than helium.[7] Their individual masses are estimated at 1.07 and 0.71 solar masses (M).[2] The system is moving closer to the Sun with a radial velocity of −47[4] km/s and will reach perihelion in about 269,000 years when it comes within roughly 17 ly (5.1 pc) of the Sun.[10]

HD 176051
Observation data
Epoch J2000      Equinox J2000
Constellation Lyra
Right ascension  18h 57m 01.60985s[1]
Declination +32° 54′ 04.5723″[1]
Apparent magnitude (V) 5.22
Spectral type G0 V + K1 V[2]
U−B color index +0.029[3]
B−V color index +0.570[3]
Radial velocity (Rv)−47.2[4] km/s
Proper motion (μ) RA: +201.96[1] mas/yr
Dec.: −145.46[1] mas/yr
Parallax (π)67.24 ± 0.37[1] mas
Distance48.5 ± 0.3 ly
(14.87 ± 0.08 pc)
Absolute magnitude (MV)4.34[5]
Period (P)22,423 d
Eccentricity (e)0.25
Argument of periastron (ω)
Semi-amplitude (K1)
3.51 km/s
Semi-amplitude (K2)
0.74 km/s
HD 176051 A
Mass1.07[2] M
Luminosity1.65[5] L
Surface gravity (log g)4.60[7] cgs
Temperature6,000[7] K
Metallicity [Fe/H]−0.11[7] dex
Age8.1[8] Gyr
HD 176051 B
Mass0.71[2] M
Other designations
ADS 11871, HR 7162, BD+32°3267, GJ 738, HD 176051, LTT 15567, SAO 67612, HIP 93017.[9]
Database references

Planetary systemEdit

A planet orbiting one of the stars was discovered through astrometric observations. However, it is not known which stellar component the planet is orbiting around.

The HD 176051 planetary system[11]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b 1.5 ± 0.3 MJ 1.76 1016 ± 40 0

The parent star is a binary star. The planet parameters are given for the 0.71 M component B (Muterspaugh et al. 2010). If the planet is orbiting the 1.07 M component A, its mass is 2.26 MJ and a = 2.02 AU.


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. ^ a b c d Muterspaugh, Matthew W.; et al. (2006). "Limits to tertiary astrometric companions in binary systems". The Astrophysical Journal. 653 (2): 1469–1479. arXiv:astro-ph/0608640. Bibcode:2006ApJ...653.1469M. doi:10.1086/508743.
  3. ^ a b Rakos, K. D.; et al. (February 1982). "Photometric and astrometric observations of close visual binaries". Astronomy and Astrophysics Supplement Series. 47: 221–235. Bibcode:1982A&AS...47..221R.
  4. ^ a b Wilson, R. E. (1953). General Catalogue of Stellar Radial Velocities. Washington D.C.: Carnegie Institute. Bibcode:1953GCRV..C......0W.
  5. ^ a b 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.
  6. ^ a b Pourbaix, D.; et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics, 424: 727–732, arXiv:astro-ph/0406573, Bibcode:2009yCat....102020P, doi:10.1051/0004-6361:20041213.
  7. ^ a b c d Luck, R. E.; Heiter, U. (2006). "Dwarfs in the local region". Astronomical Journal. 131 (6): 3069–3092. Bibcode:2006AJ....131.3069L. doi:10.1086/504080.
  8. ^ Holmberg, J.; et al. (2007). "The Geneva-Copenhagen survey of the Solar neighbourhood. II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk". Astronomy & Astrophysics. 475: 519–537. arXiv:0707.1891. Bibcode:2007A&A...475..519H. doi:10.1051/0004-6361:20077221.
  9. ^ a b "Simbad Query Result: HD 176051 -- Spectroscopic binary". Simbad. Centre de Données astronomiques de Strasbourg. Retrieved 2009-05-07.
  10. ^ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, A35.
  11. ^ Schneider, J. "Notes for star HD 176051 b". The Extrasolar Planets Encyclopaedia. Retrieved 2010-10-22.

External linksEdit