Kruger 60

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Kruger 60 A/B
Observation data
Epoch J2000      Equinox
Constellation Cepheus
Kruger 60 A
Right ascension 22h 27m 59.4677s[1]
Declination +57° 41′ 45.150″[1]
Apparent magnitude (V) 9.59
Kruger 60 B
Right ascension 22h 27m 59.568s[1]
Declination +57° 41′ 45.28″[1]
Apparent magnitude (V) 11.40
Characteristics
Spectral type M3V/M4V[2]
U−B color index 1.27/1.3
B−V color index 1.65/1.8
Variable type None/Flare star
Astrometry
Radial velocity (Rv) –33.1/–31.9 km/s
Proper motion (μ) RA: –870.23 mas/yr
Dec.: –471.10 mas/yr
Parallax (π) 247.5 ± 1.5[3] mas
Distance 13.18 ± 0.08 ly
(4.04 ± 0.02 pc)
Absolute magnitude (MV) 11.76/13.46
Details
Mass 0.271/0.176[4] M
Radius 0.35/0.24[5] R
Luminosity 0.010/0.0034 L
Temperature 3180/2890 K K
Metallicity –0.04[6]
Orbit[7]
Primary Kruger 60 A
Companion Kruger 60 B
Period (P) 44.67 yr
Semi-major axis (a) 2.383"
Eccentricity (e) 0.410
Inclination (i) 167.2°
Longitude of the node (Ω) 154.5°
Periastron epoch (T) 1970.22
Argument of periastron (ω)
(primary)
211.0°
Other designations
DO Cephei, G 232-075, GJ 860 A/B, BD +56°2783, HD 239960, LHS 3814/3815, GCTP 5438.00, ADS 15972, Vys 207 A/B, HIP 110893.[8]

Kruger 60 (DO Cephei) is a binary star system located 13.15 light-years from the Sun. These red dwarf stars orbit each other every 44.6 years.

The larger, primary star is designated component A, while the secondary, smaller star is labeled component B. Component A has about 27% of the Sun's mass and 35% of the Sun's radius. Component B has about 18% of the Sun's mass and 24% of the Sun's radius.[4][5] Component B is a flare star and has been given the variable star designation "DO Cephei".[9] It is an irregular flare that typically doubles in brightness and then returns to normal over an 8 minute period.[citation needed]

On average, the two stars are separated by 9.5 AUs, which is roughly the average distance of Saturn from the Sun. However, their eccentric mutual orbit causes their distance to vary between 5.5 AUs at periastron, to 13.5 at apastron.[citation needed]

This system is orbiting through the Milky Way at a distance from the core that varies from 7–9 kpc with an orbital eccentricity of 0.126–0.130.[10] The closest approach to the Sun will occur in about 88,600 years when this system will come within 1.95 parsecs.[11]

Distance[edit]

Kruger 60 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Woolley et al. (1970) 253 ± 3 3.95 ± 0.05 12.89 ± 0.15 [12]
Gliese & Jahreiß (1991) 251.9 ± 2.3 3.97 ± 0.04 12.95 ± 0.12 [13]
van Altena et al. (1995) 251.5 ± 3.7 3.98 ± 0.06 12.97 ± 0.19 [14]
Perryman et al. (1997) (Hipparcos) 249.52 ± 3.03 4.01 ± 0.05 13.07 ± 0.16 [15]
Perryman et al. (1997) (Tycho) (A) 225.00 ± 25.60 4.4+0.6
−0.5
14.5+1.9
−1.5
[16]
Perryman et al. (1997) (Tycho) (B) (absents) [17]
Söderhjelm (1999) 247.5 ± 1.5 4.04+0.025
−0.024
13.18 ± 0.08 [3]
van Leeuwen (2007) 249.94 ± 1.87 4.001 ± 0.03 13.05 ± 0.1 [18]
RECONS TOP100 (2012) 248.06 ± 1.39[note 1] 4.031+0.023
−0.022
13.15 ± 0.07 [19]

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

References[edit]

  1. ^ a b c d Perryman, M. A. C. et al.; Lindegren; Kovalevsky; Hoeg; Bastian; Bernacca; Crézé; Donati; Grenon et al. (1997). "The Hipparcos Catalogue". Astronomy and Astrophysics 323: L49–L52. Bibcode:1997A&A...323L..49P. 
  2. ^ Henry, Todd J.; et al. (October 1994). "The solar neighborhood, 1: Standard spectral types (K5-M8) for northern dwarfs within eight parsecs". The Astronomical Journal 108 (4): 1437–1444. Bibcode:1994AJ....108.1437H. doi:10.1086/117167. 
  3. ^ a b Söderhjelm, Staffan (1999). "HIP 110893". Visual binary orbits and masses post Hipparcos. Retrieved 2014-10-21. 
  4. ^ a b Delfosse, X.; Forveille; Ségransan; Beuzit; Udry; Perrier; Mayor; et al. (December 2000). "Accurate masses of very low mass stars. IV. Improved mass-luminosity relations". Astronomy and Astrophysics 364: 217–224. arXiv:astro-ph/0010586. Bibcode:2000A&A...364..217D. 
  5. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy and Astrophysics 367 (2): 521–524. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451.  The data is from the Vizier II/224 catalogue.
  6. ^ Bonfils, X.; et al. (November 2005). "Metallicity of M dwarfs. I. A photometric calibration and the impact on the mass-luminosity relation at the bottom of the main sequence". Astronomy and Astrophysics 442 (2): 635–642. arXiv:astro-ph/0503260. Bibcode:2005A&A...442..635B. doi:10.1051/0004-6361:20053046.  Only listed for component A.
  7. ^ Heintz, W. D. (August 1986). "Orbits of 20 visual binaries". Astronomy and Astrophysics Supplement Series 65 (2): 411–417. Bibcode:1986A&AS...65..411H. 
  8. ^ "NSV 14168 – Variable Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2009-09-28. 
  9. ^ White, Stephen M.; et al. (December 1989). "A VLA survey of nearby flare stars". Astrophysical Journal Supplement Series 71: 895–904. Bibcode:1989ApJS...71..895W. doi:10.1086/191401. 
  10. ^ Allen, C.; Herrera; Herrera, M. A. (1998). "The galactic orbits of nearby UV Ceti stars". Revista Mexicana de Astronomia y Astrofisica 34: 37–46. Bibcode:1998larm.confE.115A. 
  11. ^ García-Sánchez, J.; et al. (November 2001). "Stellar encounters with the solar system". Astronomy and Astrophysics 379 (2): 634–659. Bibcode:2001A&A...379..634G. doi:10.1051/0004-6361:20011330. 
  12. ^ Woolley R.; Epps E. A.; Penston M. J.; Pocock S. B. (1970). "Woolley 860". Catalogue of stars within 25 parsecs of the Sun. Retrieved 2014-10-21. 
  13. ^ Gliese, W. and Jahreiß, H. (1991). "Gl 860". Preliminary Version of the Third Catalogue of Nearby Stars. Retrieved 2014-10-21. 
  14. ^ Van Altena W. F., Lee J. T., Hoffleit E. D. (1995). "GCTP 5438". The General Catalogue of Trigonometric Stellar Parallaxes, Fourth Edition. Retrieved 2014-10-21. 
  15. ^ Perryman et al. (1997). "HIP 110893". The Hipparcos and Tycho Catalogues. Retrieved 2014-10-21. 
  16. ^ Perryman et al. (1997). "HIP 110893". The Hipparcos and Tycho Catalogues. Retrieved 2014-10-21. 
  17. ^ Perryman et al. (1997). "TYC 3991-92-2". The Hipparcos and Tycho Catalogues. Retrieved 2014-10-21. 
  18. ^ van Leeuwen F. (2007). "HIP 110893". Validation of the new Hipparcos reduction. Retrieved 2014-10-21. 
  19. ^ "RECONS TOP100". THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars). 2012. Retrieved 2014-10-21. 

Notes[edit]

  1. ^ Weighted parallax based on parallaxes from van Altena et al. (1995) and Söderhjelm (1999).

Further reading[edit]