| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 19 40 05.79185 |
| Declination | +18° 00′ 50.0046″ |
| Apparent magnitude (V) | 6.13 |
| Characteristics | |
| Spectral type | G0V or F4III |
| B−V color index | 0.434±0.004 |
| Astrometry | |
| Radial velocity (Rv) | +1.667±0.0024 km/s |
| Proper motion (μ) | RA: +14.630 mas/yr Dec.: −20.160 mas/yr |
| Parallax (π) | 8.5307 ± 0.1848 mas |
| Distance | 382 ± 8 ly (117 ± 3 pc) |
| Absolute magnitude (MV) | 0.82 |
| Orbit | |
| Primary | A |
| Companion | B |
| Period (P) | 101.606±0.003 d |
| Semi-major axis (a) | ≥26.4±0.2 Gm |
| Eccentricity (e) | 0.117±0.007 |
| Periastron epoch (T) | 2,442,478.0±0.8 HJD |
| Semi-amplitude (K1) (primary) | 19.0±0.1 km/s |
| Orbit | |
| Primary | AB |
| Companion | C |
| Period (P) | 3,385±7 d |
| Semi-major axis (a) | 0.074±0.001" (407±6 Gm) |
| Eccentricity (e) | 0.073±0.010 |
| Inclination (i) | 104.6±0.5° |
| Periastron epoch (T) | 2,442,880±40 HJD |
| Argument of periastron (ω) (secondary) | 91.4±4.1° |
| Semi-amplitude (K1) (primary) | 8.5±0.1 km/s |
| Details | |
| A | |
| Mass | 1.99 M☉ |
| Radius | 17.0+1.7 −1.6 R☉ |
| Luminosity | 236.1+5.9 −5.7 L☉ |
| Surface gravity (log g) | 3.41 cgs |
| Temperature | 5,488+275 −258 K |
| Rotational velocity (v sin i) | 25.3 km/s |
| Age | 1.00 Gyr |
| Other designations | |
| BD+22°2731, HD 129132, HIP 71729, HR 5472, SAO 83458, WDS J14404+2159AB, GSC 01483-00948 | |
| Database references | |
| SIMBAD | data |
HD 129132 is a triple star system in the northern constellation of Boötes. It is dimly visible to the naked eye with a combined apparent visual magnitude of 6.13. The distance to this system is approximately 382 light years based on parallax, and it is drifting further away from the Sun with a radial velocity of +1.7 km/s.
This system was found to be a spectroscopic binary by the Dominion Astrophysical Observatory in 1923. It was then shown to be a triple star system in 1937 by William E. Harper and Guy H. Blanchet. The inner pair have an orbital period of 101.6 days and an eccentricity of 0.117, with the primary forming the visible component of this pair. The third component forms a visual system with the inner pair, orbiting with a period of 9.27 years and an eccentricity of 0.073.
The primary component appears to be an aging giant star with a stellar classification of F4III, although it has also been classed as a G-type main-sequence star of type G0V. It is around a billion years old with twice the mass of the Sun. The star has expanded to 17 times the Sun's radius and is radiating 236 times the luminosity of the Sun at an effective temperature of 5,488 K. It is spinning with a projected rotational velocity of 25.3 km/s.
References
- ^ 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.
- ^ 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.
- ^ Harlan, E. A.; Taylor, D. C. (March 1970). "MK classifications for F- and G-type stars. II". Astronomical Journal. 75 (2): 165–166. Bibcode:1970AJ.....75..165H. doi:10.1086/110956.
- ^ Cowley, A. P.; Bidelman, W. P. (February 1979). "MK spectral types for some F and G stars". Publications of the Astronomical Society of the Pacific. 91: 83–86. Bibcode:1979PASP...91...83C. doi:10.1086/130446.
- ^ Barlow, D. J.; Scarfe, C. D. (December 1991). "The Spectroscopic-Speckle Triple System HR 5472". Astronomical Journal. 102: 2098. Bibcode:1991AJ....102.2098B. doi:10.1086/116034.
- ^ Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. S2CID 119511744. 21.
- "HD 129132". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-02-03.
- Harper, W. E.; Blanchet, G. H. (July 1937). "The spectroscopic orbits of H. R. 5472". Publications of the Dominion Observatory Ottawa. 7: 99-104. Bibcode:1937PDAO....7...99H.
- Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical Masses of a Selected Sample of Orbital Binaries". Astronomy & Astrophysics. 546: 5. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. A69.
