Astronomy:Tau Orionis

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Short description: Star in the constellation Orion
τ Orionis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Orion
Right ascension  05h 17m 36.38856s[1]
Declination −06° 50′ 39.8702″[1]
Apparent magnitude (V) 3.58[2]
Characteristics
Spectral type B5 III[3]
U−B color index −0.47[2]
B−V color index −0.11[2]
Astrometry
Radial velocity (Rv)+20.1[4] km/s
Proper motion (μ) RA: −17.61[1] mas/yr
Dec.: −9.24[1] mas/yr
Parallax (π)6.60 ± 0.15[1] mas
Distance490 ± 10 ly
(152 ± 3 pc)
Details
Mass6.2±0.1[5] M
Radius5.4[6] R
Luminosity933[7] L
Temperature10,829[7] K
Rotational velocity (v sin i)40[8] km/s
Age63.1±15.6[5] Myr
Other designations
τ Ori, 20 Orionis, BD−07° 1028, HD 34503, HIP 24674, HR 1735, SAO 131952.[9]
Database references
SIMBADdata

Tau Orionis (τ Ori, τ Orionis) is a solitary[10] star in the constellation Orion. If an imaginary line is drawn north-west between the stars Rigel and Mintaka, Tau Orionis can be found roughly one-sixth of the way to Mintaka. It is visible to the naked eye with an apparent visual magnitude of 3.58.[2] Based upon an annual parallax shift of 6.6 mas,[1] it is located around 490 light years from the Sun.

This is a B-type giant star with a stellar classification of B5III5 III.[3] It has around 5.4[6] times the radius of the Sun and 6.2[5] times the Sun's mass. The star shines with 933[7] times the solar luminosity from its outer atmosphere at an effective temperature of 10,829[7] K. it is around 63[5] million years old, with a peculiar velocity through space of 16.9 km/s.[5]

Tau Orionis has three visual companions: magnitude 11.0 component B at an angular separation of 33.30″ along a position angle of 251°; magnitude 10.9 component C lying some 3.80″ from component B; and magnitude 10.9 component D at 36.0″ from τ Ori along a position angle of 51°, all as of 2011.[11]

Proper names

According to Richard H. Allen, this star, along with β Eri, λ Eri and ψ Eri were Al Kursiyy al Jauzah, "the Chair (or "Footstool") of the Central One".[12] However, per the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Kursiyy al Jauzah were the title for just three stars: β Eri as Cursa, ψ Eri as Al Kursiyy al Jauzah I and λ Eri as Al Kursiyy al Jauzah II, excluding this star.[13]

In Chinese, 玉井 (Yù Jǐng), meaning Jade Well, refers to an asterism consisting of τ Orionis, β Eridani, λ Eridani and ψ Eridani.[14] Consequently, the Chinese name for τ Orionis itself is 玉井四 (Yù Jǐng sì, English: the Fourth Star of Jade Well.).[15] From this Chinese title, the name Yuh Tsing is derived.[12]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Crawford, D. L. et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal 76: 1058, doi:10.1086/111220, Bibcode1971AJ.....76.1058C. 
  3. 3.0 3.1 Abt, H. A. (September 1985), "Visual multiples. VIII - 1000 MK types", Astrophysical Journal Supplement Series 59: 95–112, doi:10.1086/191064, Bibcode1985ApJS...59...95A. 
  4. Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Carnegie Institute of Washington, D.C.), Bibcode1953GCRV..C......0W. 
  5. 5.0 5.1 5.2 5.3 5.4 Tetzlaff, N. et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T. 
  6. 6.0 6.1 Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics 367 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  7. 7.0 7.1 7.2 7.3 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode2012MNRAS.427..343M. 
  8. Abt, Helmut A. et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal 573 (1): 359–365, doi:10.1086/340590, Bibcode2002ApJ...573..359A. 
  9. "tau Ori". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=tau+Ori. 
  10. Eggleton, P. P.; Tokovinin, A. A. (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, Bibcode2008MNRAS.389..869E. 
  11. Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode2001AJ....122.3466M. 
  12. 12.0 12.1 Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 218. ISBN 0-486-21079-0. https://archive.org/details/starnamestheirlo00alle/page/218. Retrieved 2010-12-12. 
  13. Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005197_1972005197.pdf, retrieved 2016-11-24. 
  14. (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN:978-986-7332-25-7.
  15. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 15 日

External links