tau Orionis
{{Short description|Star in the constellation Orion}}
{{Starbox begin
| name = τ Orionis
}}
{{Starbox observe
| epoch = J2000.0
| constell = Orion
| dec = {{DEC|−06|50|39.8702}}
}}
{{Starbox character
| r-i =
| variable =
}}
{{Starbox astrometry
| parallax = 6.60
| p_error = 0.15
| absmag_v =
}}
{{Starbox orbit
| period_unitless = 90.29 days
| eccentricity = 0.834
| node = 156
}}
{{Starbox detail
| component1 = A
| mass = 6.6
| component2 = B
| mass2 = 5.3
}}
{{Starbox catalog
| names = τ Ori, 20 Orionis, BD−07°1028, HD 34503, HIP 24674, HR 1735, SAO 131952.
}}
{{Starbox reference
| Simbad = tau+Ori
}}
{{Starbox end}}
Tau Orionis (τ Ori, τ Orionis) is a binary 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 a combined apparent visual magnitude of 3.58. Based upon an annual parallax shift of 6.6 mas, it is located around 490 light years distant.
This is a spectroscopic binary system with an orbital period of 90 days and a very high eccentricity of 0.834. It is a heartbeat star, showing variations on its apparent magnitude during to the close periastron passage. The components have masses of {{solar mass|6.6 and 5.3}} and a combined stellar classification of B5 III. The star has a peculiar velocity through space of 16.9 km/s.
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.
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". 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.
In Chinese, {{lang|zh|玉井}} ({{lang|zh-Latn|Yù Jǐng}}), meaning Jade Well, refers to an asterism consisting of τ Orionis, β Eridani, λ Eridani and ψ Eridani.{{in lang|zh}} 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}}. Consequently, the Chinese name for τ Orionis itself is {{lang|zh|玉井四}} ({{lang|zh-Latn|Yù Jǐng sì}}, {{langx|en|the Fourth Star of Jade Well}}.).{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060715.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 15 日] {{Webarchive|url=https://web.archive.org/web/20110716123306/http://aeea.nmns.edu.tw/2006/0607/ap060715.html |date=2011-07-16 }} From this Chinese title, the name Yuh Tsing is derived.
References
{{reflist|refs=
| title=Validation of the new Hipparcos reduction
| last1=van Leeuwen | first1=F.
| journal=Astronomy and Astrophysics
| volume=474 | issue=2 | pages=653–664 | date=2007
| arxiv=0708.1752 | bibcode=2007A&A...474..653V
| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}
| display-authors=1 | last1=Mason | first1=B. D.
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| last4=Douglass | first4=G. G. | last5=Worley | first5=C. E.
| title=The Washington Visual Double Star Catalog
| year=2014 | bibcode=2001AJ....122.3466M
| doi = 10.1086/323920 | postscript=. | volume=122 | journal=The Astronomical Journal | issue=6 | pages=3466–3471| doi-access=free }}
| display-authors=1 | last1=Tetzlaff | first1=N.
| last2=Neuhäuser | first2=R. | last3=Hohle | first3=M. M.
| title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun
| journal=Monthly Notices of the Royal Astronomical Society
| volume=410 | pages=190–200 | year=2011
| issue=1 | doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | arxiv=1007.4883
| bibcode=2011MNRAS.410..190T | s2cid=118629873 | postscript=. }}
| last1=Abt | first1=H. A.
| title=Visual multiples. VIII - 1000 MK types
| journal=Astrophysical Journal Supplement Series
| volume=59 | date=September 1985 | pages=95–112
| doi=10.1086/191064 | bibcode=1985ApJS...59...95A
| postscript=. | doi-access=free}}
| display-authors=1 | last1=Crawford | first1=D. L.
| last2=Barnes | first2=J. V. | last3=Golson | first3=J. C.
| title=Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere
| journal=The Astronomical Journal
| year=1971 | pages=1058 | volume=76
| bibcode=1971AJ.....76.1058C | doi=10.1086/111220
| postscript=. }}
| last=Wilson | first=R. E. | year=1953
| title=General Catalogue of Stellar Radial Velocities
| journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institute of Washington, D.C.
| bibcode=1953GCRV..C......0W | postscript=. }}
| last=Allen
| first=R. H.
| year=1963
| authorlink=Richard Hinckley Allen
| title=Star Names: Their Lore and Meaning
| url=https://archive.org/details/starnamestheirlo00alle/page/218
| accessdate=2010-12-12
| edition=Reprint
| publisher=Dover Publications Inc
| location=New York, NY
| isbn=0-486-21079-0
| page=[https://archive.org/details/starnamestheirlo00alle/page/218 218]
| url-access=registration
}}
| url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005197_1972005197.pdf
| first1=Jack W. | last1=Rhoads
| title=Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars
| publisher=Jet Propulsion Laboratory, California Institute of Technology
| date=November 15, 1971 | accessdate=2016-11-24 | postscript=. }}
| title=tau Ori
| accessdate=2016-11-24 | postscript=. }}
}}
External links
- {{citation
| first1=James B. | last1=Kaler | date=January 23, 2009
| title=Tau Orionis | work=Stars | publisher=University of Illinois
| url=http://stars.astro.illinois.edu/sow/tauori.html
| access-date=2016-11-18 | postscript=. }}
{{Stars of Orion|state=collapsed}}
{{DEFAULTSORT:Tau Orionis}}
Category:Orion (constellation)