Astronomy:HD 129132

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Short description: Triple star system in the constellation Boötes
HD 129132
Observation data
Equinox J2000.0]] (ICRS)
Constellation Boötes
Right ascension  19h 40m 05.79185s[1]
Declination +18° 00′ 50.0046″[1]
Apparent magnitude (V) 6.13[2]
Characteristics
Spectral type G0V[3] or F4III[4]
B−V color index 0.434±0.004[2]
Astrometry
Radial velocity (Rv)+1.667±0.0024[1] km/s
Proper motion (μ) RA: +14.630[1] mas/yr
Dec.: −20.160[1] mas/yr
Parallax (π)8.5307 ± 0.1848[1] mas
Distance382 ± 8 ly
(117 ± 3 pc)
Absolute magnitude (MV)0.82
Orbit[5]
PrimaryA
CompanionB
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[5]
PrimaryAB
CompanionC
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
Mass1.99[6] M
Radius17.0+1.7
−1.6
[1] R
Luminosity236.1+5.9
−5.7
[1] L
Surface gravity (log g)3.41[6] cgs
Temperature5,488+275
−258
[1] K
Rotational velocity (v sin i)25.3[6] km/s
Age1.00[6] Gyr
Other designations
BD+22°2731, HD 129132, HIP 71729, HR 5472, SAO 83458, WDS J14404+2159AB, GSC 01483-00948[7]
Database references
SIMBADdata

HD 129132 is a triple star[5] system in the northern constellation of Boötes. It is dimly visible to the naked eye with a combined apparent visual magnitude of 6.13.[2] 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.[1]

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.[8] 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.[5][9]

The primary component appears to be an aging giant star with a stellar classification of F4III,[4] although it has also been classed as a G-type main-sequence star of type G0V.[3] It is around a billion years old with twice the mass of the Sun.[6] The star has expanded to 17[1] times the Sun's radius and is radiating 236[1] times the luminosity of the Sun at an effective temperature of 5,488 K.[1] It is spinning with a projected rotational velocity of 25.3 km/s.[6]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Harlan, E. A.; Taylor, D. C. (March 1970). "MK classifications for F- and G-type stars. II". Astronomical Journal 75 (2): 165–166. doi:10.1086/110956. Bibcode1970AJ.....75..165H. 
  4. 4.0 4.1 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. doi:10.1086/130446. Bibcode1979PASP...91...83C. 
  5. 5.0 5.1 5.2 5.3 Barlow, D. J.; Scarfe, C. D. (December 1991). "The Spectroscopic-Speckle Triple System HR 5472". Astronomical Journal 102: 2098. doi:10.1086/116034. Bibcode1991AJ....102.2098B. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal 153 (1): 19. doi:10.3847/1538-3881/153/1/21. 21. Bibcode2017AJ....153...21L. 
  7. "HD 129132". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+129132. 
  8. Harper, W. E.; Blanchet, G. H. (July 1937). "The spectroscopic orbits of H. R. 5472". Publications of the Dominion Observatory Ottawa 7: 99-104. Bibcode1937PDAO....7...99H. 
  9. 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. doi:10.1051/0004-6361/201219774. A69. Bibcode2012A&A...546A..69M.