Astronomy:HD 89571

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Short description: Binary star in the constellation Camelopardalis
HD 89571
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Camelopardalis
Right ascension  10h 29m 41.6297s[1]
Declination +84° 15′ 06.949″[1]
Apparent magnitude (V) 5.51±0.01[2]
Characteristics
Spectral type A9 V[3]
U−B color index +0.06[2]
B−V color index +0.23[2]
Astrometry
Radial velocity (Rv)3.5±2[4] km/s
Proper motion (μ) RA: −145.145[1] mas/yr
Dec.: −21.494[1] mas/yr
Parallax (π)23.0490 ± 0.3729[1] mas
Distance142 ± 2 ly
(43.4 ± 0.7 pc)
Absolute magnitude (MV)+2.48[5]
Orbit[6]
PrimaryA
CompanionB
Period (P)2.20±0.03 yr
Semi-major axis (a)0.0142±0.0006″
Eccentricity (e)0.26±0.11
Details
A
Mass1.69[7] M☉
Radius1.79[1] R☉
Luminosity8.4[8] L☉
Surface gravity (log g)4.27[9] cgs
Temperature7,535[10] K
Metallicity [Fe/H]+0.04[11] dex
Rotational velocity (v sin i)134±7[10] km/s
Age710[7] Myr
B
Mass0.38[7] M☉
Other designations
Database references
SIMBADdata

HD 89571 (HR 4062) is a binary star[12] located in the northern circumpolar constellation Camelopardalis. It is faintly visible to the naked eye with a combined apparent magnitude of 5.51[2] and is estimated to be 142 light years[1] away from the Solar System. However, it is receding with a heliocentric radial velocity of 3.5 km/s.[4]

The primary has a stellar classification of A9 V,[3] indicating that it is an ordinary A-type main-sequence star. David S. Evans gave it a slightly warmer class of A6 V[13] while Cowley et al. classified it as F0 IV,[14] indicating a F-type subgiant. Nevertheless, the two components take roughly 2 years to orbit each other at a mean separation of 14.2 mas.[6]

The components have masses of 1.69 M☉ and 0.38 M☉,[7] with the latter being a probable M-type star. HD 89571 has a radius of 1.79 R☉[1] and a luminosity of 8.4 L☉.[8] This yields an effective temperature of 7,535 K,[10] giving a white hue. It is estimated to be 710 million years old[7] and spins rapidly with a projected rotational velocity of 134 km/s;[10] it has a near solar metallicity, equating to an iron abundance 110% that of the Sun.[11]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI.". Astronomy and Astrophysics Supplement Series 89: 415. ISSN 0365-0138. Bibcode: 1991A&AS...89..415O. 
  3. ↑ 3.0 3.1 Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series 99: 135. doi:10.1086/192182. ISSN 0067-0049. Bibcode: 1995ApJS...99..135A. 
  4. ↑ 4.0 4.1 Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". International Astronomical Union 30: 57. Bibcode: 1967IAUS...30...57E. 
  5. ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. 
  6. ↑ 6.0 6.1 Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (October 2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics 546: A69. doi:10.1051/0004-6361/201219774. ISSN 0004-6361. Bibcode: 2012A&A...546A..69M. 
  7. ↑ 7.0 7.1 7.2 7.3 7.4 De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I. et al. (26 November 2013). "The VAST Survey – III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society 437 (2): 1216–1240. doi:10.1093/mnras/stt1932. ISSN 0035-8711. Bibcode: 2014MNRAS.437.1216D. 
  8. ↑ 8.0 8.1 Chandler, Colin Orion; McDonald, Iain; Kane, Stephen R. (17 February 2016). "The Catalog of Earth-Like Exoplanet Survey Targets (CELESTA): A Database of Habitable Zones Around Nearby Stars". The Astronomical Journal 151 (3): 59. doi:10.3847/0004-6256/151/3/59. Bibcode: 2016AJ....151...59C. 
  9. ↑ Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. ISSN 0004-6361. Bibcode: 1999A&A...352..555A. 
  10. ↑ 10.0 10.1 10.2 10.3 Reiners, A. (January 2006). "Rotation- and temperature-dependence of stellar latitudinal differential rotation". Astronomy & Astrophysics 446 (1): 267–277. doi:10.1051/0004-6361:20053911. ISSN 0004-6361. Bibcode: 2006A&A...446..267R. 
  11. ↑ 11.0 11.1 Netopil, Martin (4 May 2017). "Metallicity calibrations for dwarf stars and giants in the Geneva photometric system". Monthly Notices of the Royal Astronomical Society 469 (3): 3042–3055. doi:10.1093/mnras/stx1077. ISSN 0035-8711. Bibcode: 2017MNRAS.469.3042N. 
  12. ↑ Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. ISSN 0035-8711. Bibcode: 2008MNRAS.389..869E. 
  13. ↑ Evans, D. S. (1966). "Fundamental data for Southern stars (6th list).". Royal Greenwich Observatory Bulletins 110: 185. Bibcode: 1966RGOB..110..185E. 
  14. ↑ Cowley, A.; Cowley, C.; Jaschek, M.; Jaschek, C. (April 1969). "A study of the bright stars. I. A catalogue of spectral classifications.". The Astronomical Journal 74: 375. doi:10.1086/110819. ISSN 0004-6256. Bibcode: 1969AJ.....74..375C.