{{Short description|Star in the constellation Hydra}} {{Starbox begin}} {{Starbox observe | epoch = [[J2000]] | constell = [[Hydra (constellation)|Hydra]]<ref name=constellation/> | ra = {{RA|11|08|43.99011}}<ref name=dr3/> | dec = {{DEC|-28|04|50.3539}}<ref name=dr3/> | appmag_v = 5.43<ref name=AllendePrieto/> }} {{Starbox character | type = [[main sequence]]<ref name=Zorec/><ref name=dr3/> | class = A1V<ref name=Zorec/> | b-v = +0.07<ref name=Johnson/> | u-b = +0.06<ref name=Johnson/> }} {{Starbox astrometry | radial_v = {{Val|16.0|7.4}}<ref name=Kharchenko/> | prop_mo_ra = −69.211<ref name=dr3/> | prop_mo_dec = −22.181<ref name=dr3/> | parallax = 18.3139 | p_error = 0.0752 | parallax_footnote = <ref name=dr3/> | absmag_v = 1.61<ref name=AllendePrieto/> }} {{Starbox detail | component1 = HD 96819 A | mass = 1.93<ref name=Waisberg/> | radius = 1.80<ref name=Waisberg/> | temperature = 8,954<!-- 10^(3.952 ± 0.007) --><ref name=Zorec/> | luminosity = 20.66<!-- 10^(1.3152 ± 0.0289) --><ref name=Zorec/> | gravity = {{Val|4.22|0.08}}<ref name=AllendePrieto/> | metal_fe = | rotational_velocity = 249<ref name=Zorec/> | age_myr = {{Val|9|1}}<ref name=Gagné2017/> | component2 = HD 96819 B | mass2 = 0.51<ref name=Waisberg/> | temperature2 = 3,792<ref name=Waisberg/> | radius2 = 0.47<ref name=Waisberg/> }} {{Starbox catalog | names = {{odlist | CD=−27°7886 | HD=96819 | HIP=54477 | HR=4334 | SAO=179577 | NSV=5101 }}<ref name=SIMBAD/> }} {{Starbox reference |Simbad=HD+96819 }} {{Starbox end}}
'''HD 96819''' is a [[star]] in the [[celestial equator|equatorial]] [[constellation]] of [[Hydra (constellation)|Hydra]]. It was formerly known by its designation '''10 Crateris''', but that name fell into disuse after constellations were redrawn and the star was no longer in [[Crater (constellation)|Crater]]. It is visible to the naked eye as a dim, white-hued star with an [[apparent visual magnitude]] of 5.43.<ref name=AllendePrieto/> [[Stellar parallax|Parallax]] measurements put it at a distance of 178 [[light year]]s away from the Sun.<ref name=dr3/> This is most likely (98.7% chance) a member of the [[TW Hydrae association]].<ref name=Gagné2017/>
This is a rapidly rotating [[A-type main-sequence star]] that is about double the mass of the [[Sun]]. It emits 20.66 times as much energy as the [[Sun]], at an [[effective temperature]] of 8,954 K. HD 96819 is currently 31.5% through its life as a [[main-sequence star]]: after that it will swell up as a [[red giant]].<ref name=Zorec/> It is a young star of around nine million years age,<ref name=Gagné2017/> and is a suspected [[variable star]].<ref name=Samus2017/> Previously thought to be a single star,<ref name=Eggleton2008/> in 2022 a companion star was discovered, making HD 96819 a binary star. The companion star has about half the mass of the Sun.<ref name=Waisberg>{{cite journal | arxiv=2206.05251 | bibcode=2023MNRAS.521.5232W | doi=10.1093/mnras/stad872 | doi-access=free | title=Binarity and beyond in a stars – I. Survey description and first results of VLTI/GRAVITY observations of VAST targets with high ''Gaia–Hipparcos'' accelerations | date=2023 | last1=Waisberg | first1=Idel | last2=Klein | first2=Ygal | last3=Katz | first3=Boaz | journal=Monthly Notices of the Royal Astronomical Society | volume=521 | issue=4 | pages=5232–5254 }}</ref>
==References== <references> <ref name=dr3>{{cite Gaia DR3|3532027383058513664}}</ref>
<ref name=constellation>{{cite constellation|HD 96819}}</ref>
<ref name=Johnson>{{cite journal|title=UBVRIJKL Photometry of the Bright Stars|author1=Johnson, H. L.|journal=Communications of the Lunar and Planetary Laboratory|volume=4|pages=99|date=1966|bibcode=1966CoLPL...4...99J}}</ref>
<ref name=Kharchenko>{{cite journal|title=Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations|author=Kharchenko, N. V.|display-authors=etal|journal=Astronomische Nachrichten|volume=328|issue=9|page=889|date=2007|bibcode=2007AN....328..889K|doi=10.1002/asna.200710776|arxiv=0705.0878|s2cid=119323941}}</ref>
<ref name=AllendePrieto>{{cite journal|title=Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures|author1=Allende Prieto, C.|author2=Lambert, D. L.|journal=Astronomy and Astrophysics|volume=352|pages=555–562|date=1999|bibcode=1999A&A...352..555A|arxiv=astro-ph/9911002}}</ref>
<ref name=Zorec>{{cite journal|bibcode=2012A&A...537A.120Z|doi=10.1051/0004-6361/201117691|arxiv=1201.2052|title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities|journal=Astronomy & Astrophysics|volume=537|pages=A120|year=2012|last1=Zorec|first1=J.|last2=Royer|first2=F.|s2cid=55586789}}</ref>
<ref name=SIMBAD>{{cite simbad|title=HD 96819|access-date=22 August 2017}}</ref>
<ref name=Samus2017>{{citation | display-authors=1 | last1=Samus | first1=N. N. | last2=Kazarovets | first2=E. V. | last3=Durlevich | first3=O. V. | last4=Kireeva | first4=N. N. | last5=Pastukhova | first5=E. N. | title=General Catalogue of Variable Stars | version=5.1 | journal=Astronomy Reports | year=2017 | volume=61 | issue=1 | pages=80−88 | doi=10.1134/S1063772917010085 | bibcode=2017ARep...61...80S | s2cid=125853869 | postscript=. }}</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 | postscript=. | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 }}</ref>
<ref name=Gagné2017>{{citation | title=BANYAN. IX. The Initial Mass Function and Planetary-mass Object Space Density of the TW HYA Association | last1=Gagné | first1=Jonathan | last2=Faherty | first2=Jacqueline K. | last3=Mamajek | first3=Eric E. | last4=Malo | first4=Lison | last5=Doyon | first5=René | last6=Filippazzo | first6=Joseph C. | last7=Weinberger | first7=Alycia J. | last8=Donaldson | first8=Jessica K. | last9=Lépine | first9=Sébastien | last10=Lafrenière | first10=David | last11=Artigau | first11=Étienne | last12=Burgasser | first12=Adam J. | last13=Looper | first13=Dagny | last14=Boucher | first14=Anne | last15=Beletsky | first15=Yuri | last16=Camnasio | first16=Sara | last17=Brunette | first17=Charles | last18=Arboit | first18=Geneviève | display-authors=1 | journal=The Astrophysical Journal Supplement Series | volume=228 | issue=2 | id=18 | pages=51 | date=February 2017 | doi=10.3847/1538-4365/228/2/18 | arxiv=1612.02881 | bibcode=2017ApJS..228...18G | s2cid=118920136 | postscript=. | doi-access=free }}</ref> </references>
{{Stars of Hydra}}
{{DEFAULTSORT:HD 96819}} [[Category:A-type main-sequence stars]] [[Category:TW Hydrae association]] [[Category:Hydra (constellation)]] [[Category:Durchmusterung objects]] [[Category:Flamsteed objects|Crateris, 10]] [[Category:Henry Draper Catalogue objects|096819]] [[Category:Hipparcos objects|054477]] [[Category:Bright Star Catalogue objects|4334]]