HD 121504

{{Short description|Yellow dwarf star in the constellation Centaurus}} {{Starbox begin | name = HD 121504 }} {{Starbox observe | epoch = J2000 | constell = [[Centaurus]]<ref name=Anderson_Francis_2012/> | ra = {{RA|13|57|17.239}}<ref name=GaiaDR3/> | dec = {{DEC|−56|02|24.16}}<ref name=GaiaDR3/> | appmag_v = 7.54<ref name=Anderson_Francis_2012/> }} {{Starbox character | type = | class = G2V<ref name=Houk1979/> | b-v = 0.593{{±|0.002}}<ref name="Mayor2004"/><ref name=Anderson_Francis_2012/> | u-b = | variable = }} {{Starbox astrometry | radial_v = 19.603{{±|0.0004}}<ref name=Soubiran_et_al_2018/> | prop_mo_ra = −249.354 | prop_mo_dec = −84.570 | pm_footnote = <ref name=GaiaDR3/> | parallax = 24.0593 | p_error = 0.0269 | parallax_footnote = <ref name=GaiaDR3/> | absmag_v = 4.27<ref name=Anderson_Francis_2012/> }} {{Starbox detail | source = | mass = 1.16{{±|0.02}}<ref name=Bonfanti_et_al_2016/> | radius = 1.15{{±|0.03}}<ref name=Bonfanti_et_al_2016/> | luminosity = 1.62{{±|0.04}}<ref name=Bonfanti_et_al_2016/> | luminosity_bolometric = | luminosity_visual = | gravity = 4.38{{±|0.03}}<ref name=Bonfanti_et_al_2016/> | temperature = 6,089{{±|47}}<ref name=Bonfanti_et_al_2016/> | metal_fe = 0.16<ref name="Mayor2004"/> | rotation = 8.6 days<ref name="Mayor2004"/> | rotational_velocity = 2.6<ref name="Mayor2004"/> | age_gyr = 1.9{{±|1.0}}<ref name=Bonfanti_et_al_2016/> }} {{Starbox catalog | names = {{odlist | CD=−55°5427 | GC=18842 | HD=121504 | HIP=68162 | LTT=5432 | NLTT=35734 | SAO=241321 | WDS=J13573-5602A }}<ref name="Simbad"/> }} {{Starbox reference | Simbad = HD+121504 | NSTED = HD 121504 }} {{Starbox end}}

'''HD 121504''' is a [[star]] with an orbiting [[exoplanet]] in the southern [[constellation]] of [[Centaurus]]. It is located at a distance of 136 [[light year]]s from the Sun based on [[stellar parallax|parallax]] measurements, and is drifting further away with a [[radial velocity]] of 19.6 km/s.<ref name=Soubiran_et_al_2018/> With an [[apparent visual magnitude]] of 7.54,<ref name=Anderson_Francis_2012/> this star is too faint to be visible to the naked eye. It shows a high [[proper motion]], traversing the [[celestial sphere]] at an [[angular rate]] of {{val|0.270|u=arcsec yr<sup>−1</sup>}}.<ref name=Luyten1995/>

The [[stellar spectrum|spectrum]] of this star presents as an ordinary [[G-type main-sequence star]], a yellow dwarf similar in appearance to the Sun, having a [[stellar classification]] of G2V.<ref name=Houk1979/> It is roughly two billion years old and is spinning with a [[rotation period]] of 8.6 days. The star has 16% more mass than the Sun and a 15% greater radius.<ref name=Bonfanti_et_al_2016/> The [[metallicity]] (the abundance of elements more massive than helium) is higher than solar.<ref name="Mayor2004"/> The star is radiating 162% of the luminosity of the Sun from its [[photosphere]] at an [[effective temperature]] of 6,089 K.<ref name=Bonfanti_et_al_2016/>

A nearby visual companion, designated as SAO 241323 has been proposed as a component of the system. However, the pair form an [[optical binary]] with an [[angular separation]] of {{val|34.2|u=arcsecond}},<ref name="Mayor2004"/> and in reality this is a white [[giant star]] located thousands of light years away.{{cn|date=December 2023}}

==Exoplanet== In 2000 the [[Geneva Extrasolar Planet Search Team]] announced the discovery of an [[extrasolar planet]] orbiting the star.<ref>{{cite web | title=European Southern Observatory: Six Extrasolar Planets Discovered | url=http://www.spaceref.com/news/viewpr.html?pid=2365 | date=7 August 2000 | publisher=SpaceRef Interactive Inc. | access-date=15 August 2009 }}</ref>

{{OrbitboxPlanet begin | table_ref = <ref name="Mayor2004"/> }} {{OrbitboxPlanet | exoplanet = [[HD 121504 b|b]] | mass = >1.22 | period = 63.33 ± 0.03 | semimajor = 0.33 | eccentricity = 0.03 ± 0.01 }} {{Orbitbox end}}

==See also== * [[List of extrasolar planets]]

==References== {{Reflist|refs=

<ref name=Anderson_Francis_2012>{{citation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name="Mayor2004">{{cite journal | title=The CORALIE survey for southern extra-solar planets XII. Orbital solutions for 16 extra-solar planets discovered with CORALIE | last1=Mayor | first1=M. | last2=Udry | first2=S. | last3=Naef | first3=D. | last4=Pepe | first4=F. | last5=Queloz | first5=D. | last6=Santos | first6=N. C. | last7=Burnet | first7=M. | display-authors=1 | journal=Astronomy and Astrophysics | volume=415 | issue=1 | pages=391–402 | year=2004 | arxiv=astro-ph/0310316 | bibcode=2004A&A...415..391M | doi=10.1051/0004-6361:20034250 | s2cid=5233877 }}</ref>

<ref name="Simbad">{{cite simbad | title=HD 121504 | access-date=2018-04-03}}</ref>

<ref name=Soubiran_et_al_2018>{{cite journal | title=Gaia Data Release 2. The catalogue of radial velocity standard stars | last1=Soubiran | first1=C. | last2=Jasniewicz | first2=G. | last3=Chemin | first3=L. | last4=Zurbach | first4=C. | last5=Brouillet | first5=N. | last6=Panuzzo | first6=P. | last7=Sartoretti | first7=P. | last8=Katz | first8=D. | last9=Le Campion | first9=J. -F. | last10=Marchal | first10=O. | last11=Hestroffer | first11=D. | last12=Thévenin | first12=F. | last13=Crifo | first13=F. | last14=Udry | first14=S. | last15=Cropper | first15=M. | last16=Seabroke | first16=G. | last17=Viala | first17=Y. | last18=Benson | first18=K. | last19=Blomme | first19=R. | last20=Jean-Antoine | first20=A. | last21=Huckle | first21=H. | last22=Smith | first22=M. | last23=Baker | first23=S. G. | last24=Damerdji | first24=Y. | last25=Dolding | first25=C. | last26=Frémat | first26=Y. | last27=Gosset | first27=E. | last28=Guerrier | first28=A. | last29=Guy | first29=L. P. | last30=Haigron | first30=R. | display-authors=1 | journal=Astronomy and Astrophysics | volume=616 | pages=A7 | year=2018 | arxiv=1804.09370 |doi=10.1051/0004-6361/201832795 | bibcode=2018A&A...616A...7S | s2cid=52952408 }}</ref>

<ref name=Houk1979>{{cite book | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | location=Ann Arbor, Michigan | publisher=Department of Astronomy, University of Michigan | volume=1 | year=1979 | bibcode=1978mcts.book.....H }}</ref>

<ref name=Bonfanti_et_al_2016>{{cite journal | title=Age consistency between exoplanet hosts and field stars | display-authors=1 | last1=Bonfanti | first1=A. | last2=Ortolani | first2=S. | last3=Nascimbeni | first3=V. | journal=Astronomy & Astrophysics | year=2016 | volume=585 | id=A5 | pages=14 | arxiv=1511.01744 | bibcode=2016A&A...585A...5B | doi=10.1051/0004-6361/201527297 | s2cid=53971692 }}</ref>

<ref name=Luyten1995>{{cite journal | title=VizieR Online Data Catalog: NLTT Catalogue (Luyten, 1979) | last=Luyten | first=W. J. | journal=VizieR Online Data Catalog | date=June 1995 | bibcode=1995yCat.1098....0L }}</ref>

}}

{{Sky|13|57|17.2375|-|56|02|24.153|144.6}} {{Stars of Centaurus}}  [[Category:G-type main-sequence stars]] [[Category:Planetary systems with one confirmed planet]] [[Category:Double stars]]  [[Category:Centaurus]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|121504]] [[Category:Hipparcos objects|068162]]