Xi Hydrae

Xi Hydrae
	Location of ξ Hydrae (circled in red)
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Hydra
Right ascension	11h 33m 00.11505s
Declination	−31° 51′ 27.4435″
Apparent magnitude (V)	3.54
Characteristics
Spectral type	G7 III
Astrometry
Radial velocity (Rv)	−4.90±0.30 km/s
Proper motion (μ)	RA: −209.62 mas/yr ; Dec.: −40.84 mas/yr
Parallax (π)	25.16±0.16 mas
Distance	129.6 ± 0.8 ly ; (39.7 ± 0.3 pc)
Absolute magnitude (MV)	+0.54
Details
Mass	2.94±0.15 M☉
Radius	10.28±0.11 R☉
Luminosity	61.0±1.5 L☉
Surface gravity (log g)	2.78±0.07 cgs
Temperature	5,034±34 K
Metallicity [Fe/H]	+0.16±0.20 dex
Rotational velocity (v sin i)	2.7 km/s
Age	510 Myr
Other designations
	ξ Hya, 288 G. Hydrae, CD−31°9083, HD 100407, HIP 56343, HR 4450, SAO 202558
Database references
SIMBAD	data

Xi Hydrae, Latinised from ξ Hydrae, is a solitary star in the equatorial constellation of Hydra. With an apparent magnitude of 3.54 it is visible to the naked eye. Based on parallax measurements, the star 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.

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. The star has 10.28 times the Sun's radius, 61 times the Sun's luminosity and an effective temperature of 5,034 K.

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.

References

1 2 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. XHIP record for this object at VizieR.
1 2 3 4 5 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.
1 2 3 Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M.
↑ 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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
1 2 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, arXiv:1506.06095, Bibcode:2015A&A...582A..49H, doi:10.1051/0004-6361/201526319, S2CID 53391939.
1 2 3 4 5 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, arXiv:2310.11302, Bibcode:2024A&A...682A.145S, doi:10.1051/0004-6361/202347136, ISSN 0004-6361. Xi Hydrae's database entry at VizieR.
↑ 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, arXiv:1002.4268, Bibcode:2010MNRAS.405.1907B, doi:10.1111/j.1365-2966.2010.16575.x, S2CID 118495267.
1 2 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. arXiv:astro-ph/0501420. Bibcode:2005A&A...436..253T. doi:10.1051/0004-6361:20042075. S2CID 118169489.
↑ "URANOMETRIA ARGENTINA". Archived from the original on 2012-02-27. Retrieved 2012-05-08.
↑ "ksi Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-22.
↑ 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.
↑ Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy, 18 (3): 216, Bibcode:1987JHA....18..209W, doi:10.1177/002182868701800305, S2CID 118445625.
↑ Frandsen, S.; Carrier, F.; Aerts, C.; Stello, D.; Maas, T.; Burnet, M.; Bruntt, H.; Teixeira, T. C.; De Medeiros, J. R.; Bouchy, F.; Kjeldsen, H.; Pijpers, F.; Christensen-Dalsgaard, J. (2002). "Detection of Solar-like oscillations in the G7 giant star ξ Hya". Astronomy and Astrophysics. 394: L5–L8. arXiv:astro-ph/0209325. Bibcode:2002A&A...394L...5F. doi:10.1051/0004-6361:20021281.

External links

Wisky.org Star Catalogue
ESO Article: The Ultrabass Sounds of the Giant Star Xi Hya.
Listen to Xi Hya (wav).

[Anderson2012-1] 1 2 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. XHIP record for this object at VizieR.

[vanLeeuwen2007-2] 1 2 3 4 5 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.

[Mallik1999-3] 1 2 3 Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M.

[deBruijne2012-4] Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.

[Heiter2015-5] 1 2 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, arXiv:1506.06095, Bibcode:2015A&A...582A..49H, doi:10.1051/0004-6361/201526319, S2CID 53391939.

[Soubiran2024-6] 1 2 3 4 5 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, arXiv:2310.11302, Bibcode:2024A&A...682A.145S, doi:10.1051/0004-6361/202347136, ISSN 0004-6361. Xi Hydrae's database entry at VizieR.

[Bruntt2010-7] 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, arXiv:1002.4268, Bibcode:2010MNRAS.405.1907B, doi:10.1111/j.1365-2966.2010.16575.x, S2CID 118495267.

[thevenin-8] 1 2 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. arXiv:astro-ph/0501420. Bibcode:2005A&A...436..253T. doi:10.1051/0004-6361:20042075. S2CID 118169489.

[gould-9] "URANOMETRIA ARGENTINA". Archived from the original on 2012-02-27. Retrieved 2012-05-08.

[SIMBAD-10] "ksi Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-22.

[Eggleton2008-11] 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.

[Wagman1987-12] Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy, 18 (3): 216, Bibcode:1987JHA....18..209W, doi:10.1177/002182868701800305, S2CID 118445625.

[frandsen-13] Frandsen, S.; Carrier, F.; Aerts, C.; Stello, D.; Maas, T.; Burnet, M.; Bruntt, H.; Teixeira, T. C.; De Medeiros, J. R.; Bouchy, F.; Kjeldsen, H.; Pijpers, F.; Christensen-Dalsgaard, J. (2002). "Detection of Solar-like oscillations in the G7 giant star ξ Hya". Astronomy and Astrophysics. 394: L5–L8. arXiv:astro-ph/0209325. Bibcode:2002A&A...394L...5F. doi:10.1051/0004-6361:20021281.