Luyten's Star

Luyten's star
Observation data
Epoch J2000      Equinox J2000
Constellation Canis Minor
Right ascension 07h 27m 24.4991s[1]
Declination +05° 13′ 32.827″[1]
Apparent magnitude (V) 9.872[2]
Characteristics
Spectral type M3.5V[3]
U−B color index 1.115[2]
B−V color index 1.571[2]
Variable type None
Astrometry
Radial velocity (Rv)+18.2[4] km/s
Proper motion (μ) RA: 571.27[1] mas/yr
Dec.: -3694.25[1] mas/yr
Parallax (π)267.36 ± 0.79[5] mas
Distance12.20 ± 0.04 ly
(3.74 ± 0.01 pc)
Absolute magnitude (MV)11.94[2]
Details
Mass0.26[3] M☉
Radius0.35[6] R☉
Surface gravity (log g)5[7] cgs
Temperature3,150 ± 100[7] K
Metallicity [Fe/H]−0.16 ± 0.20[4] dex
Rotation115.6±19.4 d[8]
Other designations
GCTP1755, BD +05°1668, GJ 273, Gl 089-019, LHS 33, LTT 12021, LFT 527, Vys 17, HIP 36208.
Database references
SIMBADdata

Luyten's Star (GJ 273) is a red dwarf in the constellation Canis Minor located at a distance of approximately 12.36 light-years (3.79 parsecs) from the Sun. It has a visual magnitude of 9.9, making it too faint to be viewed with the unaided eye. It is named after Willem Jacob Luyten, who, in collaboration with Edwin G. Ebbighausen, first determined its high proper motion in 1935.[9]

This star is approximately a quarter the mass of the Sun[3] and has 35% of the Sun's radius.[6] Luyten's Star is at the maximum mass at which a red dwarf can be fully convective, which means that most if not all of the star forms an extended convection zone.[10] It has a stellar classification of M3.5V,[3] with the V luminosity class indicating this is a main-sequence star that is generating energy through the thermonuclear fusion of hydrogen at its core. The projected rotation rate of this star[11] is too low to be measured, but is no greater than 1 km/s.[12] Measurements of periodic variation in surface activity suggest a leisurely rotation period of roughly 116 days.[8] The effective temperature of the star's outer envelope is a relatively cool 3,150 K, giving the star the characteristic red-orange hue of an M-type star.[7][13]

At present, Luyten's Star is moving away from the Solar System. The closest approach occurred about 13,000 years ago when it came within 3.67 parsecs.[14] The star is currently located 1.2 light years distant from Procyon, and the latter would appear as a visual magnitude −4.5 star in the night sky of a hypothetical planet orbiting Luyten's Star.[15] The closest encounter between the two stars occurred about 600 years ago when Luyten's Star was at its minimal distance of about 1.12 ly from Procyon.[16] The space velocity components of Luyten's Star are U = +16, V = −66 and W = −17 km/s.[16][17][18]

See also

References

  1. 1 2 3 4 Perryman, M. A. C.; et al. (1997), "The Hipparcos Catalogue", Astronomy and Astrophysics 323: L49–L52, Bibcode:1997A&A...323L..49P
  2. 1 2 3 4 Koen, C.; et al. (July 2002), "UBV(RI)C photometry of Hipparcos red stars", Monthly Notices of the Royal Astronomical Society 334 (1): 20–38, Bibcode:2002MNRAS.334...20K, doi:10.1046/j.1365-8711.2002.05403.x
  3. 1 2 3 4 The One Hundred Nearest Stars, Research Consortium On Nearby Stars, 2009-01-01, retrieved 2009-09-03
  4. 1 2 Nidever, David L.; et al. (August 2002), "Radial Velocities for 889 Late-Type Stars", The Astrophysical Journal Supplement Series 141 (2): 503–522, arXiv:astro-ph/0112477, Bibcode:2002ApJS..141..503N, doi:10.1086/340570
  5. ↑ Gatewood, George (2008). "Astrometric Studies of Aldebaran, Arcturus, Vega, the Hyades, and Other Regions". The Astronomical Journal 136 (1): 452–460. Bibcode:2008AJ....136..452G. doi:10.1088/0004-6256/136/1/452.
  6. 1 2 Lacy, C. H. (August 1977), "Radii of nearby stars: an application of the Barnes-Evans relation", Astrophysical Journal Supplement Series 34: 479–492, Bibcode:1977ApJS...34..479L, doi:10.1086/190459
  7. 1 2 3 Viti, S.; et al. (August 2008), "A potential new method for determining the temperature of cool stars", Monthly Notices of the Royal Astronomical Society 388 (3): 1305–1313, arXiv:0805.3297, Bibcode:2008MNRAS.388.1305V, doi:10.1111/j.1365-2966.2008.13489.x
  8. 1 2 Suárez Mascareño, A.; et al. (September 2015), "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators", Monthly Notices of the Royal Astronomical Society 452 (3): 2745−2756, arXiv:1506.08039, Bibcode:2015MNRAS.452.2745S, doi:10.1093/mnras/stv1441.
  9. ↑ Luyten, W. J.; Ebbighausen, E. G. (September 1935), "A Faint Star of Large Proper Motion", Harvard College Observatory Bulletin (900): 1–3, Bibcode:1935BHarO.900....1L
  10. ↑ Reiners, A.; Basri, G. (March 2009), "On the magnetic topology of partially and fully convective stars", Astronomy and Astrophysics 496 (3): 787–790, arXiv:0901.1659, Bibcode:2009A&A...496..787R, doi:10.1051/0004-6361:200811450
  11. ↑ This is denoted by v sin i, where v is the rotational velocity at the equator and i is the inclination to the line of sight.
  12. ↑ Reiners, A. (May 2007), "The narrowest M-dwarf line profiles and the rotation-activity connection at very slow rotation", Astronomy and Astrophysics 467 (1): 259–268, arXiv:astro-ph/0702634, Bibcode:2007A&A...467..259R, doi:10.1051/0004-6361:20066991
  13. ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16
  14. ↑ García-Sánchez, J.; et al. (2001). "Stellar encounters with the solar system". Astronomy and Astrophysics 379: 634–659. Bibcode:2001A&A...379..634G. doi:10.1051/0004-6361:20011330.
  15. ↑ Schaaf, Fred (2008). The Brightest Stars: Discovering the Universe Through the Sky's Most Brilliant Stars. John Wiley and Sons. p. 169. ISBN 0-471-70410-5.
  16. 1 2 "Annotations on LHS 33 object". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-04-21.
  17. ↑ Delfosse, X.; Forveille, T.; Perrier, C.; Mayor, M. (March 1998). "Rotation and chromospheric activity in field M dwarfs". Astronomy and Astrophysics 331: 581–595. Bibcode:1998A&A...331..581D.
  18. ↑ "ARICNS star page of GJ 273". Astronomisches Rechen-Institut Heidelberg. Retrieved 2010-04-21.

Notes

    External links

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