Xi Hydrae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Hydra[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | 3.54[3] |
| Characteristics | |
| Spectral type | G7 III[3] |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[4] km/s |
| Proper motion (μ) | RA: −209.62[2] mas/yr Dec.: −40.84[2] mas/yr |
| Parallax (π) | 25.16±0.16 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | +0.54[1] |
| Details | |
| Mass | Script error: No such module "val".[5] Template:Solar mass |
| Radius | Script error: No such module "val".[6] Template:Solar radius |
| Luminosity | Script error: No such module "val".[6] Template:Solar luminosity |
| Surface gravity (log g) | Script error: No such module "val".[6] cgs |
| Temperature | Script error: No such module "val".[6] K |
| Metallicity [Fe/H] | Script error: No such module "val".[5] dex |
| Rotational velocity (v sin i) | 2.7[7] km/s |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| ξ Hya, 288 G. Hydrae,[8] CD−31°9083, HD 100407, HIP 56343, HR 4450, SAO 202558[9] | |
| Database references | |
| SIMBAD | data |
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Xi Hydrae, Latinised from ξ Hydrae, is a solitary[10] 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.[11]
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 Template:Solar mass. This puts its age at about Script error: No such module "val"..[12] The star has 10.28 times the Sun's radius, 61 times the Sun's luminosity and an effective temperature of Script error: No such module "val"..[6]
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
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- ↑ a b Template:Cite XHIP
- ↑ a b c d e Script error: No such module "citation/CS1".
- ↑ a b c Script error: No such module "citation/CS1".
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- ↑ a b Script error: No such module "citation/CS1".
- ↑ a b c d e Script error: No such module "citation/CS1". Xi Hydrae's database entry at VizieR.
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Template:Cite simbad
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
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External links
- Wisky.org Star Catalogue
- ESO Article: The Ultrabass Sounds of the Giant Star Xi Hya.
- Listen to Xi Hya (wav).