HD 158614

HD 158614 is a visual binary star system in the equatorial constellation of Ophiuchus. The system is visible to the naked eye with a combined apparent visual magnitude of +5.31.[2] It is located at a distance of 53.3 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −77 km/s[5] and is predicted to come to within 11.0 light-years in around 196,000 years.[9] The system has been included as a candidate member of the Zeta Herculis moving group.[10] However, chemical abundances appear to rule that out.[11]

HD 158614
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ophiuchus
Right ascension 17h 30m 23.79699s[1]
Declination −01° 03′ 46.4882″[1]
Apparent magnitude (V) +5.31[2] (6.02 + 5.93)[3]
Characteristics
Evolutionary stage Subgiant[4]
Spectral type G9IV-V + G9IV-V[3]
B−V color index +0.715±0.013[5]
Astrometry
Radial velocity (Rv)−76.98±0.05[5] km/s
Proper motion (μ) RA: −127.77[1] mas/yr
Dec.: −168.61[1] mas/yr
Parallax (π)61.19 ± 0.68 mas[1]
Distance53.3 ± 0.6 ly
(16.3 ± 0.2 pc)
Absolute magnitude (MV)4.24[5]
Orbit[3]
Period (P)46.34±0.021 yr
Semi-major axis (a)977.±3.3 mas
Eccentricity (e)0.168±0.0025
Inclination (i)99.1±0.11°
Longitude of the node (Ω)332.3±0.13°
Periastron epoch (T)1870.0±0.16 Byr
Argument of periastron (ω)
(secondary)		148.±1.3°
Details
A
Mass0.963±0.005[6] M☉
Radius1.7[2] R☉
Luminosity2.5[2] L☉
Surface gravity (log g)4.00[2] cgs
Temperature5,500±150[2] K
Age12.3[7] Gyr
B
Mass0.951±0.005[6] M☉
Other designations
STF 2173, BD−00°3300, GJ 678, HIP 85667, HR 6516, SAO 141702, WDS J17304-0104[8]
Database references
SIMBADdata

The pair were found to be a double star by F. G. W. Struve in 1827 and given the catalogue identifier Σ 2173 (now STF 2173). Since then it has completed multiple orbits,[12] yielding orbital elements showing a period of 46.3 years and an eccentricity of 0.17.[3] The two components have similar spectra that match a stellar classification of G9IV-V.[3] They show almost no luminosity variation; one of the pair appears to vary by 0.002 in magnitude.[4] Both components have a slightly lower mass than the Sun: 96% and 95%, respectively.[6] The system is estimated to be 12.3 billion years old.[7]

This binary was included in a search for brown dwarfs that turned up no large companions.

See also

References
  1. van Leeuwen, F. (November 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. Malagnini, M. L.; Morossi, C. (November 1990). "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars". Astronomy and Astrophysics Supplement Series. 85 (3): 1015–1019. Bibcode:1990A&AS...85.1015M.
  3. Pourbaix, D. (2000). "Resolved double-lined spectroscopic binaries: A neglected source of hypothesis-free parallaxes and stellar masses". Astronomy and Astrophysics Supplement Series. 145 (2): 215–222. Bibcode:2000A&AS..145..215P. doi:10.1051/aas:2000237.
  4. Lockwood, G. W. (1998). Balasubramaniam, K. S.; Harvey, Jack; Rabin, D. (eds.). "Luminosity and Chromospheric Variations of Solar Analog Stars". Synoptic Solar Physics -- 18th NSO/Sacramento Peak Summer Workshop Held at Sunspot; New Mexico 8-12 September 1997. ASP Conference Series. 140: 261. Bibcode:1998ASPC..140..261L.
  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.
  6. Andrade, Manuel (October 2019). "Colour-dependent accurate modelling of dynamical parallaxes and masses of visual binaries. Application to the VB+SB2 systems with definitive orbits". Astronomy & Astrophysics. 630: 11. Bibcode:2019A&A...630A..96A. doi:10.1051/0004-6361/201936199. A96.
  7. Casagrande, L.; et al. (2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey". Astronomy & Astrophysics. 530 (A138): 21. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. S2CID 56118016.
  8. "HD 158614". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-11-20.
  9. 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.
  10. Porto de Mello, G. F.; da Silva, L. (1991). "On the physical existence of the Zeta HER moving group - A detailed analysis of Phi exp 2 Pavonis". Astronomical Journal. 102: 1816–1825. Bibcode:1991AJ....102.1816P. doi:10.1086/116006.
  11. Ferreira, Letícia D.; et al. (March 2010). "On The Physical Existence of The Zeta Reticuli Moving Group: A Chemical Composition Analysis". Chemical Abundances in the Universe: Connecting First Stars to Planets, Proceedings of the International Astronomical Union, IAU Symposium. 265: 360–361. Bibcode:2010IAUS..265..360F. doi:10.1017/S174392131000092X.
  12. Batten, A. H.; et al. (March 1991). "The Binary System Sigma 2173". Publications of the Astronomical Society of the Pacific. 103: 294. Bibcode:1991PASP..103..294B. doi:10.1086/132818. S2CID 123341219.
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