White Dwarfs


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Related to White Dwarfs: Neutron stars

White Dwarfs

 

(astronomy), very dense small hot stars consisting of degenerate gas. The mass of an ordinary white dwarf averages about 1, the radius about 0.2, and the luminosity about 0.01 of the corresponding values of the sun. The average density of a white dwarf ranges from 104 to 106 g/cm3. The first white dwarf, a satellite of Sirius (a white star 10,000 times fainter than Sirius), was discovered from the distorted movements of the main star caused by attraction of the satellite. The discovery of dwarf stars confirmed the physical theory which holds that the size of bodies of degenerate gas is inversely proportional to their mass. Dwarf stars are considered the final stage in the evolution of ordinary stars after exhaustion of the thermonuclear sources of energy. They may also be related to pulsars.

A. G. MASEVICH

References in periodicals archive ?
A collision of galaxies might also create shock waves that speed the rate at which white dwarfs steal material from a companion, suggests Mario Livio of the Space Telescope Science Institute in Baltimore.
Professor Boris Gansicke of the Department of Physics at the University of Warwick, who led the study, said the destructive process which caused the discs of dust around these distant white dwarfs is likely to one day play out in our own solar system.
Ordinarily, these elements would sink into the star quickly and disappear, so the atoms are probably raining down on the white dwarf as the planets break apart.
As with any archaeological relic, the white dwarfs contain the history of a bygone era.
This white dwarf, located in the constellation Aquarius, is so cool that its carbon has crystallized - in other words, it's like a diamond, with a mass similar to that of our Sun.
Where the accretor is always a white dwarf, the donor star can be either a (helium or hybrid) white dwarf, a low-mass helium star or an evolved main-sequence star.
The thermonuclear explosion of a white dwarf star produces such supernovas.
According to Farihi, using Hubble to analyze the atmospheres of white dwarfs is the best method for finding the signatures of solid planet chemistry and determining their composition.
White dwarfs are about the same size as Earth and they slowly cool and fade over time - billions of yearsm which allows it to retain heat long enough to warm a nearby world.
British astronomers scouring data from a major star-mapping study have now identified two white dwarfs with large amounts of oxygen in their atmospheres.
At the end of its life, the sun will become a white dwarf.
The 127 contributions are organized into eight sections: white dwarf structure and evolution; white dwarf mass distribution and luminosity function; white dwarfs in stellar clusters and the galactic halo; white dwarfs in large surveys; atmospheres, abundances and magnetic fields; white dwarf dust disks and planetary systems; white dwarfs in binaries; and variable white dwarfs.