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]
| 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] |
| Distance | 53.3 ± 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 | |
| Mass | 0.963±0.005[6] M☉ |
| Radius | 1.7[2] R☉ |
| Luminosity | 2.5[2] L☉ |
| Surface gravity (log g) | 4.00[2] cgs |
| Temperature | 5,500±150[2] K |
| Age | 12.3[7] Gyr |
| B | |
| Mass | 0.951±0.005[6] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
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.[citation needed]
See also
editReferences
edit- ^ a b c d e 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.
- ^ a b c d e f 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.
- ^ a b c d e 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.
- ^ a b 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.
- ^ a b c d 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.
- ^ a b c 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.
- ^ a b 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.
- ^ "HD 158614". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-11-20.
- ^ 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.
- ^ 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.
- ^ Ferreira, Letícia D.; et al. (March 2010). "On the Physical Existence of the Zeta Reticuli Moving Group: A Chemical Composition Analysis". Proceedings of the International Astronomical Union. 265: 360–361. Bibcode:2010IAUS..265..360F. doi:10.1017/S174392131000092X.
- ^ 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.