# Delta2 Tauri

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> Markdown URL: https://mediated.wiki/source/Delta2_Tauri.md
> Source: https://en.wikipedia.org/wiki/Delta2_Tauri
> Source revision: 1345573703
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{{short description|Star in the constellation Taurus}}
{{DISPLAYTITLE:Delta<sup>2</sup> Tauri}}
{{other stars by Bayer designation|Delta Tauri{{!}}δ Tauri}}
{{Starbox begin
 | name = Delta<sup>2</sup> Tauri
}}
{{Starbox image
| image = 280px
| caption=Location of δ<sup>2</sup> Tauri in the [Hyades](/source/Hyades_(star_cluster)), indicated by its [Flamsteed designation](/source/Flamsteed_designation) 64
}}
{{Starbox observe
 | epoch = [J2000.0](/source/J2000.0)
 | equinox = [J2000.0](/source/J2000.0) ([ICRS](/source/International_Celestial_Reference_System))
 | constell = [Taurus](/source/Taurus_(constellation))
 | ra = {{RA|04|24|05.75985}}<ref name=vanLeeuwen2007/>
 | dec = {{DEC|+17|26|38.8583}}<ref name=vanLeeuwen2007/>
 | appmag_v = +4.80<ref name=Johnson1966/>
}}
{{Starbox character
 | type = [main sequence](/source/main_sequence)<ref name=zorec2012/>
 | class = A2&nbsp;Vs<ref name=Paunzen2001/>
 | b-v = +0.15<ref name=Johnson1966/>
 | u-b = +0.12<ref name=Johnson1966/>
 | variable = 
}}
{{Starbox astrometry
 | radial_v = +37.1<ref name=Gebran2016/>
 | prop_mo_ra = +108.16<ref name=vanLeeuwen2007/>
 | prop_mo_dec = −34.66<ref name=vanLeeuwen2007/>
 | parallax = 20.21
 | p_error = 0.40
 | parallax_footnote = <ref name=vanLeeuwen2007/>
 | absmag_v = +1.62<ref name=Eggen1998/>
}}
{{Starbox detail
 | source = 
 | mass = 1.79<ref name=David2015/>
 | radius = 1.8<ref name=PasinettiFracassini2001/>
 | luminosity = 27<ref name=zorec2012/>
 | temperature = 7,997<ref name=Gebran2016/>
 | gravity = 4.15<ref name=Gebran2016/>
 | metal_fe = +0.14<ref name=Gebran2016/>
 | rotational_velocity = 42<ref name=Gebran2016/>
 | age_myr = 449<ref name=David2015/>
}}
{{Starbox catalog
 | names = {{odlist | B=δ<sup>2</sup>&nbsp;Tau | F=64&nbsp;Tauri | BD=+17°714 | FK5= | HD=27819 | HIP=20542 | HR=1380 | SAO=93907  }}<ref name=SIMBAD/>
}}
{{Starbox reference
 | Simbad = del02+Tau
}}
{{Starbox end}}
'''Delta<sup>2</sup> Tauri''' ('''δ<sup>2</sup> Tauri''') is a solitary,<ref name=Eggleton2008/> white-hued [star](/source/star) in the [zodiac](/source/zodiac) [constellation](/source/constellation) of [Taurus](/source/Taurus_(constellation)). Based upon an annual [parallax](/source/parallax) shift of 20.21&nbsp;[mas](/source/milliarcsecond) as seen from Earth,<ref name=vanLeeuwen2007/> it is located roughly 161&nbsp;[light year](/source/light_year)s distant from the [Sun](/source/Sun). It is separated from [δ<sup>1</sup> Tauri](/source/Delta1_Tauri) by 0.3° on the sky<ref name=OMeara2016/> and is faintly visible to the naked eye with an [apparent visual magnitude](/source/apparent_visual_magnitude) of +4.80.<ref name=Johnson1966/> The star is considered a member of the [Hyades cluster](/source/Hyades_(star_cluster)).<ref name=Gebran2010/>

At the estimated age of 449 million years,<ref name=David2015/> this is an [A-type main-sequence star](/source/A-type_main-sequence_star) with a [stellar classification](/source/stellar_classification) of A2&nbsp;Vs,<ref name=Paunzen2001/> where the 's' suffix indicates narrow (sharp) [absorption line](/source/absorption_line)s. It has 1.8<ref name=David2015/> times the [mass of the Sun](/source/mass_of_the_Sun) and about 1.8<ref name=PasinettiFracassini2001/> times the [Sun's radius](/source/Sun's_radius). The star is radiating 27<ref name=zorec2012/> times the [Sun's luminosity](/source/Sun's_luminosity) from its [photosphere](/source/photosphere) at an [effective temperature](/source/effective_temperature) of 7,997&nbsp;K.<ref name=Gebran2016/>

δ<sup>2</sup> Tauri is a source of [X-ray emission](/source/X-ray_astronomy) with a luminosity of {{Val|101.1e20|ul=W}}. Since A-type stars are not normally a source of X-rays, this emission may be coming from an unknown companion or from a line of sight source.<ref name=Schroeder2007/>

==References==
<references>
<ref name=vanLeeuwen2007>{{citation
 | 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=. }}</ref>

<ref name=Gebran2010>{{citation
 | title=Chemical composition of A and F dwarfs members of the Hyades open cluster
 | last1=Gebran | first1=M. | last2=Vick | first2=M.
 | last3=Monier | first3=R. | last4=Fossati | first4=L.
 | journal=Astronomy and Astrophysics | postscript=.
 | volume=523 | id=A71 | pages=13 | date=November 2010
 | doi=10.1051/0004-6361/200913273 | bibcode=2010A&A...523A..71G |arxiv = 1006.5284 | s2cid=7164596 }}</ref>

<ref name=OMeara2016>{{citation
 | title=Deep-Sky Companions: The Caldwell Objects
 | first1=Stephen James | last1=O'Meara
 | publisher=[Cambridge University Press](/source/Cambridge_University_Press)
 | year=2016 | isbn=978-1107083974 | page=195 | postscript=.
 | url=https://books.google.com/books?id=MMfxDAAAQBAJ&pg=PA195 }}</ref>

<ref name=PasinettiFracassini2001>{{citation | display-authors=1
 | last1=Pasinetti Fracassini | first1=L. E. | last2=Pastori | first2=L.
 | last3=Covino | first3=S. | last4=Pozzi | first4=A.
 | title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)
 | edition=Third | journal=Astronomy and Astrophysics
 | volume=367 | pages=521–524 | date=February 2001
 | issue=2 | doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P
 | arxiv=astro-ph/0012289 | s2cid=425754 | postscript=. }}</ref>

<ref name=Schroeder2007>{{citation
 | title=X-ray emission from A-type stars
 | last1=Schröder | first1=C. | last2=Schmitt | first2=J. H. M. M.
 | journal=Astronomy and Astrophysics | postscript=.
 | volume=475 | issue=2 | date=November 2007 | pages=677–684
 | doi=10.1051/0004-6361:20077429 | bibcode=2007A&A...475..677S | doi-access=free }}</ref>

<ref name=Eggleton2008>{{citation
 | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A.
 | title=A catalogue of multiplicity among bright stellar systems
 | journal=[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society)
 | volume=389 | issue=2 | pages=869–879 | date=September 2008
 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E
 | arxiv=0806.2878 | s2cid=14878976 | postscript=. }}</ref>

<ref name=zorec2012>{{citation
 | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities
 | last1=Zorec|first1=J.|last2=Royer|first2=F.
 | journal=Astronomy & Astrophysics
 | volume=537 | pages=A120 | year=2012
 | doi=10.1051/0004-6361/201117691 | bibcode=2012A&A...537A.120Z
 | arxiv=1201.2052 | s2cid=55586789| postscript=. }}</ref>

<ref name=David2015>{{citation
 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A.
 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets
 | journal=The Astrophysical Journal
 | volume=804 | issue=2 | pages=146 | year=2015
 | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146
 | arxiv=1501.03154 | s2cid=33401607 | postscript=. }}</ref>

<ref name=Gebran2016>{{citation
 | display-authors=1 | first1=M. | last1=Gebran
 | first2=W. | last2=Farah | first3=F. | last3=Paletou
 | first4=R. | last4=Monier | first5=V. | last5=Watson
 | title=A new method for the inversion of atmospheric parameters of A/Am stars
 | journal=Astronomy & Astrophysics
 | volume=589 | date=May 2016 | id=A83 | pages=10
 | bibcode=2016A&A...589A..83G  | doi=10.1051/0004-6361/201528052
 | arxiv=1603.01146 | s2cid=118549566 | postscript=. }}</ref>

<ref name=Paunzen2001>{{citation
 | display-authors=1 | last1=Paunzen | first1=E.
 | last2=Duffee | first2=B. | last3=Heiter | first3=U.
 | last4=Kuschnig | first4=R. | last5=Weiss | first5=W. W.
 | title=A spectroscopic survey for λ Bootis stars. II. The observational data
 | journal=Astronomy and Astrophysics | postscript=. 
 | volume=373 | pages=625–632 | date=July 2001
 | issue=2 | doi=10.1051/0004-6361:20010630 | bibcode=2001A&A...373..625P | doi-access=free }}</ref>

<ref name=Johnson1966>{{citation | display-authors=1
 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B.
 | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z.
 | title=UBVRIJKL photometry of the bright stars
 | journal=Communications of the Lunar and Planetary Laboratory
 | volume=4 | issue=99 | year=1966
 | page=99 | bibcode=1966CoLPL...4...99J | postscript=. }}</ref>

<ref name=Eggen1998>{{citation
 | title=The Age Range of Hyades Stars
 | last1=Eggen | first1=Olin J. | postscript=.
 | journal=The Astronomical Journal
 | volume=116 | issue=1 | pages=284–292 | date=July 1998
 | doi=10.1086/300413 | bibcode=1998AJ....116..284E | doi-access=free }}</ref>

<ref name=SIMBAD>{{cite simbad
 | title=del02 Tau | access-date=2017-08-07 }}</ref>
</references>

{{Stars of Taurus|state=collapsed}}

Category:A-type main-sequence stars
Tauri, Delta
Category:Taurus (constellation)
Category:Durchmusterung objects
Tauri, 064
027819
020542
1380
Category:Hyades (star cluster)

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Adapted from the Wikipedia article [Delta2 Tauri](https://en.wikipedia.org/wiki/Delta2_Tauri) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Delta2_Tauri?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.