Xi Hydrae
Encyclopedia
Xi Hydrae is a third-magnitude star
in the constellation
Hydra
. The star is situated 130 light-years from Earth, and has a radius about 10 times that of the Sun, and a luminosity nearly 60 times as large. The star is now approaching the end of its life, and is about to expand its outer envelope to become a red giant
star.
The star Xi Hya was particularly interesting in the field of asteroseismology
when an international group of astronomers discovered that it behaves like a giant sub-ultra-bass musical instrument
.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Hydra
Hydra (constellation)
Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake...
. The star is situated 130 light-years from Earth, and has a radius about 10 times that of the Sun, and a luminosity nearly 60 times as large. The star is now approaching the end of its life, and is about to expand its outer envelope to become a red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
star.
The star Xi Hya was particularly interesting in the field of asteroseismology
Asteroseismology
Asteroseismology also known as stellar seismology is the science that studies the internal structure of pulsating stars by the interpretation of their frequency spectra. Different oscillation modes penetrate to different depths inside the star...
when an international group of astronomers discovered that it behaves like a giant sub-ultra-bass musical instrument
Musical instrument
A musical instrument is a device created or adapted for the purpose of making musical sounds. In principle, any object that produces sound can serve as a musical instrument—it is through purpose that the object becomes a musical instrument. The history of musical instruments dates back to the...
.
External links
- Wisky.org Star Catalogue
- ESO Article: The Ultrabass Sounds of the Giant Star Xi Hya.
- Listen to Xi Hya (mp3).