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Latest White dwarf Stories

2008-07-11 15:00:09

Almost two months ago my newborn son began his life just as stars go through a life cycle of their own. Stars are formed from within a nebula, a cloud of gas and dust. Over time, hydrogen gas is pulled together by gravity and begins to spin faster and faster until the gas heats up to spark nuclear fusion in the core, and a new star is formed. In the first stages of life, a star fuses hydrogen gas into helium. Ninety percent of stars are in this main sequence stage. The sun, about 4.5...

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2008-07-10 08:00:00

Imagine having three clocks in your house, each chiming at a different time. Astronomers have found the equivalent of three out-of-sync "clocks" in the ancient open star cluster NGC 6791. The dilemma may fundamentally challenge the way astronomers estimate cluster ages, researchers said. Using NASA's Hubble Space Telescope to study the dimmest stars in the cluster, astronomers uncovered three different age groups. Two of the populations are burned-out stars called white dwarfs. One group of...

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2008-06-03 10:20:00

A team of stellar astronomers is engaged in an interstellar CSI (crime scene investigation). They have two suspects, traces of assault and battery, but no corpse. The southern planetary nebula SuWt 2 is the scene of the crime, some 6,500 light-years from Earth in the direction of the constellation Centaurus. SuWt 2 consists of a bright, nearly edge-on glowing ring of gas. Faint lobes extend perpendicularly to the ring, giving the faintest parts of the nebula an hourglass shape. These glowing...

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2008-05-01 12:29:26

Discovery helps solve riddle of where the carbon white dwarfs come from, and what happens to their hydrogen and helium University of Texas at Austin astronomers Michael H. Montgomery and Kurtis A. Williams, along with graduate student Steven DeGennaro, have predicted and confirmed the existence of a new type of variable star, with the help of the 2.1-meter Otto Struve Telescope at McDonald Observatory. The discovery is announced in today's issue of Astrophysical Journal Letters. This research...

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2008-04-01 11:05:00

Scientists working at the Dublin Institute for Advanced Studies have found a clutch of jets from newborn brown dwarfs. In her talk on Tuesday 1 April at the RAS National Astronomy Meeting in Belfast, postdoctoral researcher Dr Emma Whelan will announce the discovery of more jets from these intriguing objects, bringing the total to 4.New stars form in cold clouds of gas and dust. These so-called stellar nurseries are not only home to forming stars (protostars) but also harbor forming brown...

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2008-03-26 17:10:00

Judi Provencal is star-struck, but not so much by the glitz and glam of Hollywood.You have to look heavenward through a telescope to see the object of her fascination--to pale stars called white dwarfs, their brilliance faded because all of their nuclear fuel has been burned up.A white dwarf is a star that is "dying," cooling down in the twilight of its life. It's what the sun will become in about 4 billion years, according to Provencal.Starting Wednesday, March 26, Provencal--who is an...

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2008-02-13 13:20:00

Using data from NASA's Chandra X-ray Observatory, scientists have reported the possible detection of a binary star system that was later destroyed in a supernova explosion. The new method they used provides great future promise for finding the detailed origin of these important cosmic events. In an article appearing in the February 14th issue of the journal Nature, Rasmus Voss of the Max Planck Institute for Extraterrestrial Physics in Germany and Gijs Nelemans of Radboud University in the...

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2008-01-29 13:50:00

A strange and violent fate awaits a white dwarf star that wanders too close to a moderately massive black hole. According to a new study, the black hole's gravitational pull on the white dwarf would cause tidal forces sufficient to disrupt the stellar remnant and reignite nuclear burning in it, giving rise to a supernova explosion with an unusual appearance. Observations of such supernovae could confirm the existence of intermediate-mass black holes, currently the subject of much debate...

2008-01-28 11:40:50

Explosions of small stars, long thought to create stellar dust, actually sweep dust away, scientists discovered. For years, researchers have observed swirling dust clouds around systems called recurring novas, which periodically explode. New images of a distant nova have now overturned astronomers' long-standing assumption that the dust originates in the blasts. Scientists recently observed the RS Ophiuchi system, where a small white dwarf star and large red giant orbit each...

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2008-01-28 15:25:00

First results from a new NASA-funded scientific instrument at the W. M. Keck Observatory in Hawaii are helping scientists overturn long-standing assumptions about powerful explosions called novae and have produced the first unified model for a nearby nova called RS Ophiuchi. "We were getting ready for a routine engineering run when all of a sudden the nova went off. It was very bright and easy to observe, so we took this opportunity and turned it into gold," says team member Marc Kuchner of...


Latest White dwarf Reference Libraries

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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...

6_dac4e7d6b8fb5cf3a1458d796b90d7a92
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...

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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...

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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
grass-comber
  • A landsman who is making his first voyage at sea; a novice who enters naval service from rural life.
According to the OED, a grass-comber is also 'a sailor's term for one who has been a farm-labourer.'