# HD 96819

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/HD_96819
> Markdown URL: https://mediated.wiki/source/HD_96819.md
> Source: https://en.wikipedia.org/wiki/HD_96819
> Source revision: 1328190068
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Star in the constellation Hydra

HD 96819 Observation data Epoch J2000 Equinox J2000 Constellation Hydra[1] Right ascension 11h 08m 43.99011s[2] Declination −28° 04′ 50.3539″[2] Apparent magnitude (V) 5.43[3] Characteristics Evolutionary stage main sequence[4][2] Spectral type A1V[4] U−B color index +0.06[5] B−V color index +0.07[5] Astrometry Radial velocity (Rv) 16.0±7.4[6] km/s Proper motion (μ) RA: −69.211[2] mas/yr Dec.: −22.181[2] mas/yr Parallax (π) 18.3139±0.0752 mas[2] Distance 178.1 ± 0.7 ly (54.6 ± 0.2 pc) Absolute magnitude (MV) 1.61[3] Details HD 96819 A Mass 1.93[7] M☉ Radius 1.80[7] R☉ Luminosity 20.66[4] L☉ Surface gravity (log g) 4.22±0.08[3] cgs Temperature 8,954[4] K Rotational velocity (v sin i) 249[4] km/s Age 9±1[8] Myr HD 96819 B Mass 0.51[7] M☉ Radius 0.47[7] R☉ Temperature 3,792[7] K Other designations NSV 5101, CD−27°7886, HD 96819, HIP 54477, HR 4334, SAO 179577[9] Database references SIMBAD data

**HD 96819** is a [star](/source/Star) in the [equatorial](/source/Celestial_equator) [constellation](/source/Constellation) of [Hydra](/source/Hydra_(constellation)). 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](/source/Crater_(constellation)). It is visible to the naked eye as a dim, white-hued star with an [apparent visual magnitude](/source/Apparent_visual_magnitude) of 5.43.[3] [Parallax](/source/Stellar_parallax) measurements put it at a distance of 178 [light years](/source/Light_year) away from the Sun.[2] This is most likely (98.7% chance) a member of the [TW Hydrae association](/source/TW_Hydrae_association).[8]

This is a rapidly rotating [A-type main-sequence star](/source/A-type_main-sequence_star) that is about double the mass of the [Sun](/source/Sun). It emits 20.66 times as much energy as the [Sun](/source/Sun), at an [effective temperature](/source/Effective_temperature) of 8,954 K. HD 96819 is currently 31.5% through its life as a [main-sequence star](/source/Main-sequence_star): after that it will swell up as a [red giant](/source/Red_giant).[4] It is a young star of around nine million years age,[8] and is a suspected [variable star](/source/Variable_star).[10] Previously thought to be a single star,[11] in 2022 a companion star was discovered, making HD 96819 a binary star. The companion star has about half the mass of the Sun.[7]

## References

1. **[^](#cite_ref-constellation_1-0)** [Roman, Nancy G.](/source/Nancy_Roman) (1987). ["Identification of a constellation from a position"](https://doi.org/10.1086%2F132034). *[Publications of the Astronomical Society of the Pacific](/source/Publications_of_the_Astronomical_Society_of_the_Pacific)*. **99** (617): 695. [Bibcode](/source/Bibcode_(identifier)):[1987PASP...99..695R](https://ui.adsabs.harvard.edu/abs/1987PASP...99..695R). [doi](/source/Doi_(identifier)):[10.1086/132034](https://doi.org/10.1086%2F132034). [Constellation record for this object](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?source=VI%2F42%2Fout&%2F%2Ftables=VI%2F42%2Fout&-c=HD+96819&-c.eq=J2000&-c.r=++2&-c.u=arcmin&-c.geom=r&-source=&-source=VI%2F42%2Fout&-out=RA1875&-out=DE1875&-out=Cst) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-dr3_2-0) [***b***](#cite_ref-dr3_2-1) [***c***](#cite_ref-dr3_2-2) [***d***](#cite_ref-dr3_2-3) [***e***](#cite_ref-dr3_2-4) [***f***](#cite_ref-dr3_2-5) [***g***](#cite_ref-dr3_2-6) Vallenari, A.; et al. (Gaia collaboration) (2023). ["*Gaia* Data Release 3. Summary of the content and survey properties"](https://doi.org/10.1051%2F0004-6361%2F202243940). *Astronomy and Astrophysics*. **674**: A1. [arXiv](/source/ArXiv_(identifier)):[2208.00211](https://arxiv.org/abs/2208.00211). [Bibcode](/source/Bibcode_(identifier)):[2023A&A...674A...1G](https://ui.adsabs.harvard.edu/abs/2023A&A...674A...1G). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202243940](https://doi.org/10.1051%2F0004-6361%2F202243940). [S2CID](/source/S2CID_(identifier)) [244398875](https://api.semanticscholar.org/CorpusID:244398875). [Gaia DR3 record for this source](https://vizier.cds.unistra.fr/viz-bin/VizieR-4?-source=+I%2F355&-from=nav&-nav=cat%3AI%2F355%26tab%3A%7BI%2F355%2Fgaiadr3%7D%26key%3Asource%3D1355%2Fgaiadr3%26HTTPPRM%3A%26-out.add%3D.%26Source%3D%3D%3D3532027383058513664%26-go+%25%23Sesame%23%25%26) at [VizieR](/source/VizieR).

1. ^ [***a***](#cite_ref-AllendePrieto_3-0) [***b***](#cite_ref-AllendePrieto_3-1) [***c***](#cite_ref-AllendePrieto_3-2) [***d***](#cite_ref-AllendePrieto_3-3) Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". *Astronomy and Astrophysics*. **352**: 555–562. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9911002](https://arxiv.org/abs/astro-ph/9911002). [Bibcode](/source/Bibcode_(identifier)):[1999A&A...352..555A](https://ui.adsabs.harvard.edu/abs/1999A&A...352..555A).

1. ^ [***a***](#cite_ref-Zorec_4-0) [***b***](#cite_ref-Zorec_4-1) [***c***](#cite_ref-Zorec_4-2) [***d***](#cite_ref-Zorec_4-3) [***e***](#cite_ref-Zorec_4-4) [***f***](#cite_ref-Zorec_4-5) Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". *Astronomy & Astrophysics*. **537**: A120. [arXiv](/source/ArXiv_(identifier)):[1201.2052](https://arxiv.org/abs/1201.2052). [Bibcode](/source/Bibcode_(identifier)):[2012A&A...537A.120Z](https://ui.adsabs.harvard.edu/abs/2012A&A...537A.120Z). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201117691](https://doi.org/10.1051%2F0004-6361%2F201117691). [S2CID](/source/S2CID_(identifier)) [55586789](https://api.semanticscholar.org/CorpusID:55586789).

1. ^ [***a***](#cite_ref-Johnson_5-0) [***b***](#cite_ref-Johnson_5-1) Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". *Communications of the Lunar and Planetary Laboratory*. **4**: 99. [Bibcode](/source/Bibcode_(identifier)):[1966CoLPL...4...99J](https://ui.adsabs.harvard.edu/abs/1966CoLPL...4...99J).

1. **[^](#cite_ref-Kharchenko_6-0)** Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". *Astronomische Nachrichten*. **328** (9): 889. [arXiv](/source/ArXiv_(identifier)):[0705.0878](https://arxiv.org/abs/0705.0878). [Bibcode](/source/Bibcode_(identifier)):[2007AN....328..889K](https://ui.adsabs.harvard.edu/abs/2007AN....328..889K). [doi](/source/Doi_(identifier)):[10.1002/asna.200710776](https://doi.org/10.1002%2Fasna.200710776). [S2CID](/source/S2CID_(identifier)) [119323941](https://api.semanticscholar.org/CorpusID:119323941).

1. ^ [***a***](#cite_ref-Waisberg_7-0) [***b***](#cite_ref-Waisberg_7-1) [***c***](#cite_ref-Waisberg_7-2) [***d***](#cite_ref-Waisberg_7-3) [***e***](#cite_ref-Waisberg_7-4) [***f***](#cite_ref-Waisberg_7-5) Waisberg, Idel; Klein, Ygal; Katz, Boaz (2023). ["Binarity and beyond in a stars – I. Survey description and first results of VLTI/GRAVITY observations of VAST targets with high *Gaia–Hipparcos* accelerations"](https://doi.org/10.1093%2Fmnras%2Fstad872). *Monthly Notices of the Royal Astronomical Society*. **521** (4): 5232–5254. [arXiv](/source/ArXiv_(identifier)):[2206.05251](https://arxiv.org/abs/2206.05251). [Bibcode](/source/Bibcode_(identifier)):[2023MNRAS.521.5232W](https://ui.adsabs.harvard.edu/abs/2023MNRAS.521.5232W). [doi](/source/Doi_(identifier)):[10.1093/mnras/stad872](https://doi.org/10.1093%2Fmnras%2Fstad872).

1. ^ [***a***](#cite_ref-Gagné2017_8-0) [***b***](#cite_ref-Gagné2017_8-1) [***c***](#cite_ref-Gagné2017_8-2) Gagné, Jonathan; et al. (February 2017), "BANYAN. IX. The Initial Mass Function and Planetary-mass Object Space Density of the TW HYA Association", *The Astrophysical Journal Supplement Series*, **228** (2): 51, [arXiv](/source/ArXiv_(identifier)):[1612.02881](https://arxiv.org/abs/1612.02881), [Bibcode](/source/Bibcode_(identifier)):[2017ApJS..228...18G](https://ui.adsabs.harvard.edu/abs/2017ApJS..228...18G), [doi](/source/Doi_(identifier)):[10.3847/1538-4365/228/2/18](https://doi.org/10.3847%2F1538-4365%2F228%2F2%2F18), [S2CID](/source/S2CID_(identifier)) [118920136](https://api.semanticscholar.org/CorpusID:118920136), 18.

1. **[^](#cite_ref-SIMBAD_9-0)** ["HD 96819"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+96819). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 22 August 2017.

1. **[^](#cite_ref-Samus2017_10-0)** Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", *Astronomy Reports*, 5.1, **61** (1): 80−88, [Bibcode](/source/Bibcode_(identifier)):[2017ARep...61...80S](https://ui.adsabs.harvard.edu/abs/2017ARep...61...80S), [doi](/source/Doi_(identifier)):[10.1134/S1063772917010085](https://doi.org/10.1134%2FS1063772917010085), [S2CID](/source/S2CID_(identifier)) [125853869](https://api.semanticscholar.org/CorpusID:125853869).

1. **[^](#cite_ref-Eggleton2008_11-0)** Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", *[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society)*, **389** (2): 869–879, [arXiv](/source/ArXiv_(identifier)):[0806.2878](https://arxiv.org/abs/0806.2878), [Bibcode](/source/Bibcode_(identifier)):[2008MNRAS.389..869E](https://ui.adsabs.harvard.edu/abs/2008MNRAS.389..869E), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2008.13596.x](https://doi.org/10.1111%2Fj.1365-2966.2008.13596.x), [S2CID](/source/S2CID_(identifier)) [14878976](https://api.semanticscholar.org/CorpusID:14878976).

v t e Constellation of Hydra List of stars in Hydra Hydra in Chinese astronomy Stars Bayer α (Alphard) β γ (Naga) δ ε (Ashlesha) ζ η θ ι (Ukdah) κ λ μ ν ξ ο π ρ σ (Minchir) τ1 τ2 υ1 (Zhang) υ2 φ1 φ2 φ3 χ1 χ2 ψ ω b1 b3 C F Flamsteed 1 2 3 6 (a) 9 10 12 (D) 14 15 17 19 20 21 23 24 25 26 27 (P) 28 29 33 (A) 34 37 44 47 48 50 51 (k) 52 (l) 54 (m) 55 56 57 58 (Solitaire) 59 60 10 Crt 17 Crt 20 Crt 2 Sex Variable R U V W TW EX HS KU LQ V361 V419 V421 V478 V484 HR 3378 3538 3749 (G) 3750 3858 (I) 3862 3919 3923 (Felis) 4162 4328 4339 (β Ant) 4445 5265 HD 72659 74156 82943 86226 86264 90156 (γ Ant) Other 2MASS 1114−2618 ESO 439-26 Gliese 328 Gliese 357 Gliese 433 Gliese 453 GJ 3634 HAT-P-30 HE 1256−2738 HE 1327−2326 LHS 2065 LHS 3003 LTT 3780 SDSS J090745.0+024507 WASP-25 WASP-36 WASP-84 WASP-166 (Filetdor) WISE 0855−0714 WISEA J1141−3326 Exoplanets Gliese 357 d HD 72659 b HD 74156 b c HD 82943 b c HD 86226 b HD 86264 b TW Hydrae b (unconfirmed) WASP-193b Star clusters Messier 48 Messier 68 NGC 5694 Price-Whelan 1 Nebulae Abell 33 Abell 35 NGC 3242 Southern Owl Nebula Galaxies Messier 83 NGC 2617 2642 2697 2708 2758 2835 2848 2865 2890 2935 2936 2937 2960 2962 2986 2992 3030 3052 3054 3081 3109 3124 3200 3285 3285B 3290 3305 3307 3308 3309 3311 3312 3313 3314 3315 3316 3336 3369 3383 3393 3402 3463 3464 3585 3621 3673 3717 3904 3923 3936 4980 4993 5042 5061 5078 5085 5101 5135 5260 5264 5495 5626 Other 3C 196.1 AM 1316−241 Arp 7 CTQ 327 ESO 510-G13 GAMA202627 GLEAM J0917−0012 Hydra A IC 535 MRC 1138−262 Peekaboo Galaxy PKS 1151−348 RX J0911.4+0551 SDSS J0841+0101 TN J0924−2201 Tololo 1247−232 ZwCl 1693 BCG Galaxy clusters Abell 754 Abell 3411 Abell 3412 Bullet Group Hickson 40 Astronomical events GW170817 Category

---
Adapted from the Wikipedia article [HD 96819](https://en.wikipedia.org/wiki/HD_96819) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/HD_96819?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.