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Star in the constellation Hydrus
Zeta Hydri , Latinized from ζ Hydri, is a single,[ 7] star in the southern constellation of Hydrus . It is faintly visible to the naked eye with an apparent magnitude of 4.83.[ 2] parallax shift of 11.47 mas ,[ 1] light years away. It is moving further away from the Sun with a radial velocity of +3.6 km/s.[ 4]
The spectrum of this star matches a stellar classification of A2 IV,[ 2] subgiant star that is in the process of evolving away from the main sequence as the supply of hydrogen at its core becomes exhausted. It has a high rate of spin, showing a projected rotational velocity of 116 km/s.[ 6] oblate shape with an equatorial bulge that is 5% larger than the polar radius.[ 8] mass of the Sun and nearly four times the Sun's radius .[ 5] [ 2] Sun's luminosity into space from its photosphere at an effective temperature of 9,144 K.[ 6]
^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics . 474 (2): 653–664. arXiv :0708.1752 Bibcode :2007A&A...474..653V . doi :10.1051/0004-6361:20078357 . S2CID 18759600 . Vizier catalog entry ^ a b c d e f g Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters . 38 (5): 331. arXiv :1108.4971 Bibcode :2012AstL...38..331A . doi :10.1134/S1063773712050015 . S2CID 119257644 . Vizier catalog entry ^ a b Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers . 42 (2): 443. Bibcode :2014JAVSO..42..443M . Vizier catalog entry ^ a b Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication . Carnegie Institution of Washington . Bibcode :1953GCRV..C......0W . LCCN 54001336 . ^ a b c 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 :astro-ph/9911002 Bibcode :1999A&A...352..555A . Vizier catalog entry ^ a b c d e David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal . 804 (2): 146. arXiv :1501.03154 Bibcode :2015ApJ...804..146D . doi :10.1088/0004-637X/804/2/146 . S2CID 33401607 . Vizier catalog entry ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society , 389 (2): 869–879, arXiv :0806.2878 Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x S2CID 14878976 . ^ Belle, G. T. (2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review . 20 (1): 51. arXiv :1204.2572 Bibcode :2012A&ARv..20...51V . doi :10.1007/s00159-012-0051-2 . S2CID 119273474 .
