HD 122430

{{Short description|Star in the constellation Hydra}} {{Starbox begin}} {{Starbox observe | epoch = J2000 | constell = [[Hydra (constellation)|Hydra]]<ref name=Anderson2012/> | ra = {{RA|14|02|22.78173}}<ref name=GaiaDR2/> | dec = {{DEC|−27|25|47.1992}}<ref name=GaiaDR2/> | appmag_v = 5.47<ref name=Anderson2012/> }} {{Starbox character | type = | class = K2–3III<ref name=houk1979/> | b-v = {{Val|1.331|0.003}}<ref name=Anderson2012/> | u-b = | variable = }} {{Starbox astrometry | radial_v = {{Val|−0.61|0.24}}<ref name=GaiaDR2/> | prop_mo_ra = {{val|−31.861|0.259}}<ref name=GaiaDR2/> | prop_mo_dec = {{val|−4.195|0.215}}<ref name=GaiaDR2/> | parallax = 7.3651 | p_error = 0.1407 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = −0.17<ref name=Anderson2012/> }} {{Starbox detail | source = <ref name=Jofré2015/> | mass = {{Val|1.62|0.19}} | radius = {{Val|21.20|2.06}} | luminosity = {{Val|189.6|4.2}}<ref name=GaiaDR2/> | gravity = {{Val|1.96|0.07}} | temperature = {{Val|4383|19|fmt=commas}} | metal_fe = {{Val|−0.08|0.04}} | rotational_velocity = {{Val|2.59|0.45}} | age_gyr = {{Val|1.98|0.67}} }} {{Starbox catalog | names = {{odlist | CD=-26°10060 | GC=18954 | GCRV=8247 | HD=122430 | HIP=68581 | HR=5265 | SAO=182182 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+122430 | EPE = HD+122430 }} {{End}}

'''HD 122430''' is single [[star]]<ref name=Eggleton2008/> in the [[celestial equator|equatorial]] [[constellation]] of [[Hydra (constellation)|Hydra]]. It has an orange hue and is faintly visible to the naked eye with an [[apparent visual magnitude]] of 5.47.<ref name=Anderson2012/> The star is located at a distance of 105.6 [[light year]]s from the [[Sun]] based on [[stellar parallax|parallax]]. It has the Bayer designation '''h Hydrae'''.<ref name = Wagman2003/>

This is an aging [[giant star]] with a [[stellar classification]] of K2–3III.<ref name=houk1979/> It has completely run out of the [[hydrogen]] [[fuel]] that keeps it stable, although it is only two billion years old,<ref name=Jofré2015/> younger than the Sun's 4.6 billion years. HD 122430 has a mass of 1.6 times and radius of 22.9 times that of the Sun.<ref name=Jofré2015/> Despite its younger age, it has slightly lower metallicity, approximately 90%. It is radiating 190<ref name=GaiaDR2/> times the [[luminosity]] of the Sun from its [[photosphere]] at an [[effective temperature]] of 4300 K.<ref name=Jofré2015/>

A candidate [[exoplanet]] was reported orbiting the star via the [[radial velocity method]] at a conference in 2003, and designated HD 122430 b. It has an [[orbital period]] of {{Convert|344.95|days|years|2|disp=out|abbr=off}} and an [[orbital eccentricity|eccentricity]] of 0.68.<ref name="Setiawan2003"/> However, a follow-up study by Soto et al. (2015) failed to detect a signal, so it remains unconfirmed.<ref name=Soto2015/>

{{OrbitboxPlanet begin | table_ref = <ref name="Setiawan2003"/> }} {{OrbitboxPlanet hypothetical | exoplanet = b | mass = >3.71 | period = {{Val|344.95|1.08}} | semimajor = 1.02 | eccentricity = {{Val|0.68|0.09}} }} {{Orbitbox end}}

== See also == * [[HD 47536]] * [[List of extrasolar planets]]

==References== {{Reflist|refs=

<ref name=SIMBAD>{{cite simbad | title=HD 117207 | access-date=2018-07-23}}</ref>

<ref name=Soto2015>{{cite journal | title=RAFT - I. Discovery of new planetary candidates and updated orbits from archival FEROS spectra | display-authors=1 | last1=Soto | first1=M. G. | last2=Jenkins | first2=J. S. | last3=Jones | first3=M. I. | journal=Monthly Notices of the Royal Astronomical Society | volume=451 | issue=3 | pages=3131–3144 | date=August 2015 | doi=10.1093/mnras/stv1144 | doi-access=free | arxiv=1505.04796 | bibcode=2015MNRAS.451.3131S }}</ref>

<ref name=Jofré2015>{{cite journal | last1=Jofré | first1=E. | last2=Petrucci | first2=R. | last3=Saffe | first3=C. | last4=Saker | first4=L. | last5=Artur de la Villarmois | first5=E. | last6=Chavero | first6=C. | last7=Gómez | first7=M. | last8=Mauas | first8=P. J. D. | title=Stellar parameters and chemical abundances of 223 evolved stars with and without planets | display-authors=1 | journal=Astronomy & Astrophysics | volume=574 | pages=A50 | year=2015 | arxiv=1410.6422 | bibcode=2015A&A...574A..50J | doi=10.1051/0004-6361/201424474 | s2cid=53666931 }}</ref>

<ref name=Eggleton2008>{{cite journal | 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 | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | s2cid=14878976 }}</ref>

<ref name=houk1979>{{cite book | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=3 | last1=Houk | first1=Nancy | location=Ann Arbor, Michigan | publisher=Department of Astronomy, University of Michigan | date=1979 | bibcode=1982mcts.book.....H }}</ref>

<ref name="Setiawan2003">{{cite conference | title=Planets around evolved stars | last1=Setiawan | first1=J. | conference=Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets, 22–25 April 2003, Heidelberg, Germany | date=October 2003 | publisher=ESA Publications Division | location=Noordwijk, Netherlands | volume=539 | pages=595–598 | bibcode=2003ESASP.539..595S | isbn=92-9092-849-2 }}</ref>

<ref name = Wagman2003>{{cite book | author = Morton Wagman | date = 2003 | title = Lost Stars: Lost, Missing, and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas-Louis de Lacaille, John Flamsteed, and Sundry Others | edition = 2 | publisher = McDonald & Woodward Publishing Company | pages = | isbn = 978-0-939923-78-6 | oclc = 1131243914 | url = https://books.google.com/books?id=TYLvAAAAMAAJ}}</ref>

}}

[[Category:K-type giants]] [[Category:Hydra (constellation)]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|122430]] [[Category:Hipparcos objects|068581]] [[Category:Bright Star Catalogue objects|5265]]