{{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, indicated by its Flamsteed designation 64 }} {{Starbox observe | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Taurus | 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<ref name=zorec2012/> | class = A2 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> Tau | F=64 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 in the zodiac constellation of Taurus. Based upon an annual parallax shift of 20.21 mas as seen from Earth,<ref name=vanLeeuwen2007/> it is located roughly 161 light years distant from the Sun. It is separated from δ<sup>1</sup> Tauri by 0.3° on the sky<ref name=OMeara2016/> and is faintly visible to the naked eye with an apparent visual magnitude of +4.80.<ref name=Johnson1966/> The star is considered a member of the Hyades cluster.<ref name=Gebran2010/>
At the estimated age of 449 million years,<ref name=David2015/> this is an A-type main-sequence star with a stellar classification of A2 Vs,<ref name=Paunzen2001/> where the 's' suffix indicates narrow (sharp) absorption lines. It has 1.8<ref name=David2015/> times the mass of the Sun and about 1.8<ref name=PasinettiFracassini2001/> times the Sun's radius. The star is radiating 27<ref name=zorec2012/> times the Sun's luminosity from its photosphere at an effective temperature of 7,997 K.<ref name=Gebran2016/>
δ<sup>2</sup> Tauri is a source of X-ray emission 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 | 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 | 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)