Latest White dwarf Stories
After 31 years of tracking the light- output of a burnt-out star from telescopes at McDonald Observatory, astronomer S.O. Kepler of Brazil's Universidade Federal do Rio Grande do Sul and a slew of University of Texas colleagues have found the most stable optical clock in the heavens.
Astronomers have glimpsed dusty debris around an essentially dead star where gravity and radiation should have long ago removed any sign of dust -- a discovery that may provide insights into our own solar system's eventual demise several billion years from now.
Amateur astronomers are being asked to help a constellation of observatories unravel the mysteries of a puzzling binary star system.
Amidst the glitter of billions of stars in the majestic spiral galaxy called the Whirlpool (M51), a massive star abruptly ends its life in a brilliant flash of light. NASA's Hubble Space Telescope snapped images of the exploding star, called Supernova (SN) 2005cs, 12 days after its discovery.
For the first time an X-ray image of a pair of interacting stars has been made by NASA's Chandra X-ray Observatory. The ability to distinguish between the interacting stars - one a highly evolved giant star and the other likely a white dwarf - allowed a team of scientists to observe an X-ray outburst from the giant star and find evidence that a bridge of hot matter is streaming between the two stars.
A University of California scientist at Los Alamos National Laboratory working with astronomers from around the world recently validated a computer model that predicts the rebirth and stellar burning and mixing processes of evolved stars. The discovery is a leap forward in our understanding of how stars like the sun evolve through violent outbursts during their evolution.
New supercomputer simulations may help explain periodic bursts of light emitted by compact binary star systems.
Scientists from Imperial College London have detected a dusty wind emitted by a star that, at the end of its life, turned into a white dwarf and then exploded as a supernova. This is the first time that a wind from this type of supernova precursor has been observed and it is also the first time that associated dust has been detected.
The center of our galaxy is hidden behind a "brick wall" of obscuring dust so thick that not even the Hubble Space Telescope can penetrate it. Astronomers Silas Laycock and Josh Grindlay (Harvard-Smithsonian Center for Astrophysics) and colleagues have lifted that veil to reveal a beautiful vista swarming with stars.
White Dwarf -- A white dwarf is a a star supported by electron degeneracy. A star like our Sun will become a white dwarf when it has exhausted its nuclear fuel. Near the end of its nuclear burning stage, such a star goes through a red giant phase and then expels most of its outer material (creating a planetary nebula) until only the hot (T > 100,000 K) core remains, which then settles down to become a young white dwarf. A typical white dwarf is half as massive as the Sun, yet only...
Stellar Evolution -- Stellar evolution is the process of formation, life, and death of stars. It is one of the major topics of cosmogony. Star Birth and Life A star starts out as an enormous cloud of gas and dust many light-years across. Star formation begins when the cloud begins to condense under its own gravity. The processes that initiate this contraction are not fully understood. The cloud fragments fuse into stellar mass clouds known as protostars. Protostars do not emit...
Nova -- A nova is an enormous nuclear explosion caused by the accretion of hydrogen onto the surface of a white dwarf star. When a white dwarf has a close companion star, the companion will often begin to have its outer atmosphere drawn away from it by the white dwarf's gravity as the companion star ages and expands into a red giant. The gases so captured consist primarily of hydrogen and helium, the two principle constituents of matter in the universe. The gases are compacted on the...
Cataclysmic Variable Star -- Cataclysmic variables are a class of binary stars containing a white dwarf and a companion star. The companion star is usually a red dwarf, although in some cases it is another white dwarf or a slightly evolved star (subgiant). Several hundreds of cataclysmic variables are known. From the observational viewpoint, cataclysmic variables are relatively easy to discover. They are usually quite blue objects, as the majority of stars are red. The variability of...
Sirius -- Sirius (Î± Canis Major, also known as the Dog Star) is the brightest star (-1.46m) in the night sky and can be seen from every inhabited region of the Earth's surface. At a distance of 8.6 light years, Sirius is also one of the nearest stars to Earth. It is a main sequence star of spectral type A0 or A1 and has a mass about 2.4 times that of the Sun. Sirius has a white dwarf companion called Sirius B which orbits it with a period close to 50 years. It was the first white...
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