Astronomy:Xi Hydrae

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Short description: Star in the constellation Hydra
Xi Hydrae
Observation data
Equinox J2000.0]] (ICRS)
Constellation Hydra[1]
Right ascension  11h 33m 00.11505s[2]
Declination −31° 51′ 27.4435″[2]
Apparent magnitude (V) 3.54[3]
Characteristics
Spectral type G7 III[3]
Astrometry
Radial velocity (Rv)−4.90±0.30[4] km/s
Proper motion (μ) RA: −209.62[2] mas/yr
Dec.: −40.84[2] mas/yr
Parallax (π)25.16 ± 0.16[2] mas
Distance129.6 ± 0.8 ly
(39.7 ± 0.3 pc)
Absolute magnitude (MV)+0.54[1]
Details
Mass2.94±0.15[5] M☉
Radius10.28±0.11[6] R☉
Luminosity61.0±1.5[6] L☉
Surface gravity (log g)2.78±0.07[6] cgs
Temperature5,034±34[6] K
Metallicity [Fe/H]+0.16±0.20[5] dex
Rotational velocity (v sin i)2.7[7] km/s
Age510[8] Myr
Other designations
ξ Hya, 288 G. Hydrae,[9] CD−31°9083, HD 100407, HIP 56343, HR 4450, SAO 202558[10]
Database references
SIMBADdata

Xi Hydrae, Latinised from ξ Hydrae, is a solitary[11] star in the equatorial constellation of Hydra. With an apparent magnitude of 3.54[3] it is visible to the naked eye. Based on parallax measurements, the tar is situated 130 light-years from Earth.

Flamsteed gave Xi Hydrae the designation 19 Crateris. He included a number of stars now within the IAU boundaries of Hydra as part of a Hydra & Crater constellation overlapping parts of both modern constellations.[12]

Charactertistics

Xi Hydrae has left the main sequence, having exhausted the supply of hydrogen in its core. Its spectrum is that of a red giant. Modelling its physical properties against theoretical evolutionary tracks shows that it has just reached the foot of the red giant branch for a star with an initial mass around 3 M☉. This puts its age at about 510 Myr.[8] The star has 10.28 times the Sun's radius, 61 times the Sun's luminosity and an effective temperature of 5,034 K.[6]

One possible non-radial oscillation mode of Xi Hydrae

The star Xi Hydrae is particularly interesting in the field of asteroseismology since it shows solar-like oscillations. Multiple frequency oscillations are found with periods between 2.0 and 5.5 hours.[13]

References

  1. ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.  XHIP record for this object at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V. 
  3. ↑ 3.0 3.1 3.2 Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics 352: 495–507, Bibcode: 1999A&A...352..495M. 
  4. ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D. 
  5. ↑ 5.0 5.1 Heiter, U.; Jofré, P.; Gustafsson, B.; Korn, A. J.; Soubiran, C.; Thévenin, F. (2015), "Gaia FGK benchmark stars: Effective temperatures and surface gravities", Astronomy & Astrophysics 582: A49, doi:10.1051/0004-6361/201526319, Bibcode: 2015A&A...582A..49H. 
  6. ↑ 6.0 6.1 6.2 6.3 6.4 Soubiran, C. et al. (2024-02-01), "Gaia FGK benchmark stars: Fundamental Teff and log g of the third version", Astronomy and Astrophysics 682: A145, doi:10.1051/0004-6361/202347136, ISSN 0004-6361, Bibcode: 2024A&A...682A.145S.  Xi Hydrae's database entry at VizieR.
  7. ↑ Bruntt, H. et al. (July 2010), "Accurate fundamental parameters for 23 bright solar-type stars", Monthly Notices of the Royal Astronomical Society 405 (3): 1907–1923, doi:10.1111/j.1365-2966.2010.16575.x, Bibcode: 2010MNRAS.405.1907B. 
  8. ↑ 8.0 8.1 Thévenin, F.; Kervella, P.; Pichon, B.; Morel, P.; Di Folco, E.; Lebreton, Y. (2005). "VLTI/VINCI diameter constraints on the evolutionary status of δ Eri, ξ Hya, η Boo". Astronomy and Astrophysics 436 (1): 253. doi:10.1051/0004-6361:20042075. Bibcode: 2005A&A...436..253T. 
  9. ↑ "URANOMETRIA ARGENTINA". http://www.uranometriaargentina.com/. 
  10. ↑ "ksi Hya". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ksi+Hya. 
  11. ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E. 
  12. ↑ Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy 18 (3): 216, doi:10.1177/002182868701800305, Bibcode: 1987JHA....18..209W. 
  13. ↑ Frandsen, S.; Carrier, F.; Aerts, C.; Stello, D.; Maas, T.; Burnet, M.; Bruntt, H.; Teixeira, T. C. et al. (2002). "Detection of Solar-like oscillations in the G7 giant star ξ Hya". Astronomy and Astrophysics 394: L5–L8. doi:10.1051/0004-6361:20021281. Bibcode: 2002A&A...394L...5F. 



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