Pulsations discovered coming from dying star
Using the 2.1-meter Otto Struve Telescope at the University of Texas `s McDonald Observatory, astronomers have discovered pulsations from the crystalized remnant of a burnt-out star.
Washington : Using the 2.1-meter Otto Struve Telescope at the University of Texas `s McDonald Observatory, astronomers have discovered pulsations from the crystalized remnant of a burnt-out star.
The finding will allow astronomers to see below the star`s atmosphere and into its interior, much like earthquakes allow geologists to study compositions below Earth`s surface.
The Texas astronomers made their discovery in collaboration with astronomers from Brazil`s Universidade Federal do Rio Grande do Sul, the University of Oklahoma, and the Smithsonian Astrophysical Observatory.
The star, GD 518, is roughly 170 light-years from Earth in the constellation Draco, but far too faint to be seen without a telescope. It is a white dwarf, a star at the end of its life cycle that is essentially just a burnt-out core, the ashy byproduct of previous epochs of nuclear fusion.
The star is unique in that much of it is likely suspended in a state more akin to a solid than a liquid or gas. The interiors of dying stars can become crystalized similar to the way in which frigid water freezes into ice.
"GD 518 is special because it is a very massive white dwarf: It has about 1.2 times the mass of the Sun, packed into a volume smaller than Earth," said lead author J. J. Hermes, a graduate student at The University of Texas at Austin.
"Few white dwarfs are endowed with so much mass, and this is by far the most massive white dwarf discovered to pulsate," he added.
The star also likely has an interior composed of heavier elements than those found in typical burnt-out stars.
The discovery of pulsations-periodic brightness changes on the surface of a star that, in this case, keep a regular tune every 400-600 seconds-will allow astronomers an unprecedented opportunity to understand what makes up this highly evolved star`s interior.
The findings appeared in the current issue of The Astrophysical Journal Letters.