{{Short description|Multiple star in the constellation Centaurus}} {{For|'''d Centauri'''|HD 117440}} {{Starbox begin | name = D Centauri }} {{Starbox observe | epoch = J2000.0 | constell = [[Centaurus]]<ref name=Anderson_Francis_2012/> | ra = {{RA|12|14|02.697}}<ref name="van Leeuwen2007"/> | dec = {{DEC|−45|43|26.10}}<ref name="van Leeuwen2007"/> | appmag_v = +5.31<ref name=Anderson_Francis_2012/> {{nowrap|(5.78 + 6.98)}}<ref name=Mason_et_al_2014/> }} {{Starbox character | type = | class = K3III<ref name=Houk1978/> {{nowrap|(K4IIIab + K2IIIb)}}<ref name=Corbally1984/> | b-v = {{val|+1.400|0.003}}<ref name=Anderson_Francis_2012/>/1.21<ref name=Corbally1984/> | u-b = +1.82/1.19<ref name=Corbally1984/> | variable = }} {{Starbox astrometry | component1 = A | radial_v = {{val|+10.27|0.68}}<ref name=GaiaDR2A/> | prop_mo_ra = −37.186<ref name=GaiaDR2A/> | prop_mo_dec = 6.606<ref name=GaiaDR2A/> | parallax = 5.3350 | p_error = 0.1399 | parallax_footnote = <ref name=GaiaDR2A/> | absmag_v = −0.88<ref name=Anderson_Francis_2012/> | component2 = B | radial_v2 = <!--Radial velocity (in km/sec)--> | prop_mo_ra2 = −33.604<ref name=GaiaDR2B/> | prop_mo_dec2 = 5.434<ref name=GaiaDR2B/> | parallax2 = 4.9297 | p_error2 = 0.0550 | parallax_footnote2 = <ref name=GaiaDR2B/> | absmag_v2 = <!--Absolute magnitude ([[UBV photometric system|Johnson-Cousins V system]])--> }} {{Starbox detail | component1 = A | mass = | radius = {{val|42.8|1.1|2.13}}<ref name=GaiaDR2A/> | luminosity = {{val|434|13}}<ref name=GaiaDR2A/> | gravity = | temperature = {{val|4026|104|50|fmt=commas}}<ref name=GaiaDR2A/> | metal_fe = | rotation = | age_myr = | rotational_velocity = | component2 = B | radius2 = {{val|13.5|1.7|1.9}}<ref name=GaiaDR2B/> | luminosity2 = {{val|90.5|1.4}}<ref name=GaiaDR2B/> | temperature2 = {{val|4853|275|392|fmt=commas}}<ref name=GaiaDR2B/> }} {{Starbox catalog | names = {{odlist | B=D Cen | HR=4652 | HD=106321 | CD=−45°7630 | HIP=59654 | SAO=223297 | GC=16703 | CCDM=J12140-4543 | WDS+J12140-4543 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+106321 }} {{Starbox end}}

'''D Centauri''' is a [[double star]] in the southern [[constellation]] of [[Centaurus]].<ref name=SIMBAD/> The system is faintly visible to the naked eye as a point of light with a combined [[apparent magnitude]] of +5.31;<ref name=Anderson_Francis_2012/> the two components are of magnitude 5.78 and 6.98, respectively.<ref name=Mason_et_al_2014/> It is located at a distance of approximately 610&nbsp;[[light year]]s from the [[Sun]] based on [[stellar parallax|parallax]], and is drifting further away with a [[radial velocity]] of ~10&nbsp;km/s.<ref name=GaiaDR2A/>

The dual nature of this star was announced by [[Carl Ludwig Christian Rümker|C. Rumker]] in 1837. As of 2015, the pair had an [[angular separation]] of {{val|2.70|ul=arcsecond}} along a [[position angle]] of 242°.<ref name=Mason_et_al_2014/> This orange-hued double has a combined [[stellar classification]] of K3III,<ref name=Houk1978/> matching an aging [[giant star]] that has exhausted the supply of hydrogen at its [[stellar core|core]]. In 1984, [[Christopher J. Corbally|C. J. Corbally]] found a class of K4IIIab for the primary and K2IIIb for the fainter secondary.<ref name=Corbally1984/>

== References == {{Reflist|colwidth=30em|refs=

<ref name=SIMBAD>{{cite simbad | title=D Cen | access-date=2021-01-28 }}</ref>

<ref name=GaiaDR2A>{{Cite Gaia DR2|6143569843526877056}}</ref>

<ref name=GaiaDR2B>{{Cite Gaia DR2|6143569843526876928}}</ref>

<ref name=Corbally1984>{{cite journal | title=Close visual binaries. I - MK classifications | last1=Corbally | first1=C. J. | journal=The Astrophysical Journal Supplement Series | volume=55 | pages=657 | year=1984 | bibcode=1984ApJS...55..657C | doi=10.1086/190973 }}</ref>

<ref name=Anderson_Francis_2012>{{cite XHIP|59654}}</ref>

<ref name="van Leeuwen2007">{{cite journal | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 }} [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=59457 Vizier catalog entry ] </ref>

<ref name=Houk1978>{{cite book | last1=Houk | first1=N. | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=2 | date=1978 | publisher=Dept. of Astronomy, University of Michigan | bibcode=1978mcts.book.....H }}</ref>

<ref name=Mason_et_al_2014>{{cite journal | display-authors=1 | last1=Mason | first1=B. D. | last2=Wycoff | first2=G. L. | last3=Hartkopf | first3=W. I. | last4=Douglass | first4=G. G. | last5=Worley | first5=C. E. | title=The Washington Visual Double Star Catalog | journal=The Astronomical Journal | year=2014 | volume=122 | pages=3466–3471 | doi=10.1086/323920 | doi-access=free | bibcode=2001AJ....122.3466M }}</ref>

}}

{{Stars of Centaurus}}

{{DEFAULTSORT:D Centauri}} [[Category:K-type giants]] [[Category:Double stars]] [[Category:Bayer objects|Centauri, D]] [[Category:Centaurus]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|106321]] [[Category:Hipparcos objects|059654]] [[Category:Bright Star Catalogue objects|4652]]