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) | 263.76 ± 1.25[3] mas |
| Distance | 12.37 ± 0.06 ly (3.79 ± 0.02 pc) |
| Absolute magnitude (MV) | 11.94[2] |
| Details | |
| Mass | 0.26[3] M☉ |
| Radius | 0.35[5] R☉ |
| Temperature | 3,150 ± 100[6] K |
| Metallicity [Fe/H] | −0.16 ± 0.20[4] dex |
| Other designations | |
Luyten's Star (GJ 273) is a red dwarf star in the constellation Canis Minor. It is located at a distance of around 12.36 light-years (3.79 parsecs) and 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.[7]
This star is approximately a quarter the mass of the Sun[3] and has 35% of the Sun's radius.[5] Luyten's Star is at the maximum mass at which a red dwarf star can be fully convective. That is, most of not all of the star forms an extended convection zone.[8] 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[9] is too low to be measured, but is no greater than 1 km/s.[10] 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.[6][11]
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.[12] 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.[13] 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.[14] The space velocity components of Luyten's Star are U = +16, V = −66 and W = -17 km/s.[14][15][16]
In Larry Niven's Known Space stories, Luyten's Star is Down's primary (known as "L5 1668", a corrupted designation).[citation needed]
[edit] See also
[edit] References
- ^ a b c d Perryman, M. A. C. et al. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics 323: L49–L52, Bibcode 1997A&A...323L..49P
- ^ a b c d 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
- ^ a b c d e The One Hundred Nearest Stars, Research Consortium on Nearby Stars, 2009-01-01, http://www.chara.gsu.edu/RECONS/TOP100.posted.htm, retrieved 2009-09-03
- ^ a b 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
- ^ a b 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
- ^ a b 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, Bibcode 2008MNRAS.388.1305V, doi:10.1111/j.1365-2966.2008.13489.x
- ^ Luyten, E. G.; Ebbighausen (September 1935), "A Faint Star of Large Proper Motion", Harvard College Observatory Bulletin (900): 1–3, Bibcode 1935BHarO.900....1L
- ^ Reiners, A.; Basri, G. (March 2009), "On the magnetic topology of partially and fully convective stars", Astronomy and Astrophysics 496 (3): 787–790, Bibcode 2009A&A...496..787R, doi:10.1051/0004-6361:200811450
- ^ 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.
- ^ 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
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16
- ^ 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.
- ^ Schaaf, Fred (2008). The Brightest Stars: Discovering the Universe Through the Sky's Most Brilliant Stars. John Wiley and Sons. p. 169. ISBN 047170410.
- ^ a b "Annotations on LHS 33 object". SIMBAD. Centre de Données astronomiques de Strasbourg. http://cdsannotations.u-strasbg.fr/annotations/simbadObject/971564. Retrieved 2010-04-21.
- ^ 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.
- ^ "ARICNS star page of GJ 273". Astronomisches Rechen-Institut Heidelberg. http://www.ari.uni-heidelberg.de/datenbanken/aricns/cnspages/4c00562.htm. Retrieved 2010-04-21.
[edit] External links
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