HD 176051

HD 176051 is a spectroscopic binary star system^[12] 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.^[10] 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.^[13]

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
Characteristics
Spectral type	G0 V + K1 V[2]
U−B color index	+0.029[3]
B−V color index	+0.570[3]
Astrometry
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 mas[1]
Distance	48.5 ± 0.3 ly (14.87 ± 0.08 pc)
Absolute magnitude (MV)	4.34[5]
Orbit[6]
Period (P)	22,423 d
Semi-major axis (a)	19.1 AU[7]
Eccentricity (e)	0.25 (0.27[7] or 0.54[8])
Argument of periastron (ω) (secondary)	102°
Semi-amplitude (K1) (primary)	3.51 km/s
Semi-amplitude (K2) (secondary)	0.74 km/s
Details
HD 176051 A
Mass	1.07[2] M☉
Radius	1.06[9] R☉
Luminosity	1.65[5] L☉
Surface gravity (log g)	4.60[10] cgs
Temperature	6,000[10] K
Metallicity [Fe/H]	−0.11[10] dex
Age	8.1[11] Gyr
HD 176051 B
Mass	0.71[2] M☉
Radius	0.81[9] R☉
Other designations
ADS 11871, HR 7162, BD+32°3267, GJ 738, HD 176051, LTT 15567, SAO 67612, HIP 93017.[12]
Database references
SIMBAD	AB
	A
	B
Exoplanet Archive	data
ARICNS	data
	data2
Extrasolar Planets Encyclopaedia	data

Planetary system

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^[14]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	1.5 ± 0.3 MJ	1.76	1016 ± 40	0	—	—

The planet parameters are given here for the 0.71 M_☉ component B.^[7] But, if instead the planet is orbiting the 1.07 M_☉ component A, its mass is 2.26 M_J with a semimajor axis of 2.02 AU.^[14]

See also

• List of star systems within 45–50 light-years
• Alpha Centauri
• Gamma Cephei

References

1. 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. S2CID 18759600.
2. 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. S2CID 15218103.
3. 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. Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Washington D.C.: Carnegie Institute. Bibcode:1953GCRV..C......0W.
5. 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.VizieR
6. Pourbaix, D.; et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics, 424: 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.VizierR (obsoleted)
7. Muterspaugh, Matthew W.; Lane, Benjamin F.; et al. (2010). "The PHASES Differential Astrometry Data Archive. V. Candidate Substellar Companions to Binary Systems". The Astronomical Journal. 140 (6): 1657–1671. arXiv:1010.4048. Bibcode:2010AJ....140.1657M. doi:10.1088/0004-6256/140/6/1657. The substellar object is a planet 1.5 ± 0.3 times the mass of Jupiter, assuming a distance of 15 pc and a stellar mass of 0.71 M_☉...
8. Simonetti, Paolo; et al. (2020). "Statistical Properties of Habitable Zones in Stellar Binary Systems". The Astrophysical Journal. 903 (2): 141. arXiv:2010.05585. Bibcode:2020ApJ...903..141S. doi:10.3847/1538-4357/abc074. S2CID 222291409.
9. Johnson, H. M.; et al. (1983). "Predicted infrared brightness of stars within 25 parsecs of the sun". The Astrophysical Journal Supplement Series. 53: 643. Bibcode:1983ApJS...53..643J. doi:10.1086/190905."VizieR−GJ 738A/738B"
10. 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.
11. 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 (2): 519–537. arXiv:0707.1891. Bibcode:2007A&A...475..519H. doi:10.1051/0004-6361:20077221. S2CID 119054949.
12. "Simbad Query Result: HD 176051 -- Spectroscopic binary". Simbad. Centre de Données astronomiques de Strasbourg. Retrieved 2009-05-07.
13. 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, S2CID 59039482, A35.
14. Schneider, J (1995). "Notes for star HD 176051 b". Extrasolar Planets Encyclopaedia. Retrieved 2010-10-22.

External links

• HD 176051 b on The Extrasolar Planets Encyclopaedia
• Candidate substellar companions of binary systems