Latest White dwarf Stories

2005-12-02 12:42:10

Fort Davis, TEXAS -- 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. The finding has implications for theories of how stars live and die, and places limits on where planets can exist around this white dwarf. Their results are being published in today's...

2005-09-09 18:35:00

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. The results are based on mid-infrared observations made with the Gemini 8-meter Frederick C. Gillett Telescope (Gemini North) on Hawaii's Mauna Kea. The Gemini observations reveal a surprisingly high abundance of dust orbiting an...

2005-08-27 09:50:00

AAVSO -- Amateur astronomers are being asked to help a constellation of observatories unravel the mysteries of a puzzling binary star system. On August 30-August 31, 2005 two space-based and four professional ground-based observatories are scheduled to observe the cataclysmic variable star AE Aqr. Each of the observatories covers a different wavelength of light and amateur astronomers have been asked to help cover the visible-light portion. "This observing campaign will take place over...

2005-08-01 15:00:00

NASA -- 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. Astronomers then compared those photos with Hubble images of the same region before the supernova blast to pinpoint the progenitor star (the star that exploded). The color image at left shows a...

2005-04-29 08:10:44

NASA -- 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. "Before this observation it was assumed that all the X-rays came from a hot disk...

2005-04-18 18:57:14

LANL -- 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. In research published recently in the journal Science, Laboratory astrophysicist Falk Herwig and his colleagues...

2005-04-06 08:20:00

RAS -- New supercomputer simulations may help explain periodic bursts of light emitted by compact binary star systems. Cataclysmic variables are binary systems that consist of a white dwarf and a normal star. The dense white dwarf drags material from its companion star, creating an accretion disc of matter around itself, and a hotspot develops where the gas stream from the star crashes into the accretion disc. On Wednesday 6th April at the RAS National Astronomy Meeting in Birmingham, Dr...

2005-04-05 08:10:00

RAS -- 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 properties of the wind hold vital clues to the kind of star that exploded. Dr Rubina Kotak, from Imperial College London, will be presenting the...

2005-01-11 14:26:29

San Diego, CA -- 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. Moreover, their hunt for specific stars associated with X-ray-emitting sources has ruled out one of two options for the nature of these X-ray sources: most...

Latest White dwarf Reference Libraries

2004-10-19 04:45:43

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...

2004-10-19 04:45:42

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...

2004-10-19 04:45:42

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...

2004-10-19 04:45:41

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...

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Word of the Day
  • The hard inner (usually woody) layer of the pericarp of some fruits (as peaches or plums or cherries or olives) that contains the seed.
This word comes from the Greek 'endon,' in, within, plus the Greek 'kardia,' heart.