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Latest White dwarf Stories

6eb426e23610ca81638360b65ac04522
2007-12-04 09:45:00

NASA's Hubble Space Telescope is providing strong evidence that white dwarfs, the burned out relics of stars, are given a "kick" when they form. The sharp vision of Hubble's Advanced Camera for Surveys uncovered the speedy white dwarfs in the ancient globular star cluster NGC 6397, a dense swarm of hundreds of thousands of stars. Before the stars burned-out as white dwarfs, they were among the most massive stars in NGC 6397. Because massive stars are thought to gather at a globular cluster's...

ee380e24a70f7effe91ac92e2f79b6321
2007-11-21 13:00:00

Astronomers may have found another way that stars evolve Astronomers have discovered white dwarf stars with pure carbon atmospheres. These stars possibly evolved in a sequence astronomers didn't know before. They may have evolved from stars that are not quite massive enough to explode as supernovae but are just on the borderline. All but the most massive two or three percent of stars eventually die as white dwarfs rather than explode as supernovae. When a star burns helium, it leaves "ashes"...

4189e8624b875e4453c9a75fec6dc69d
2007-11-01 10:00:00

Cambridge, MA - Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that a supernova discovered last year was caused by two colliding white dwarf stars. The white dwarfs were siblings orbiting each other. They slowly spiraled inward until they merged, touching off a titanic explosion. CfA observations show the strongest evidence yet of what was, until now, a purely theoretical mechanism for creating a supernova. "This finding shows that nature may be richer than...

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2007-09-13 00:00:00

Using NASA's Swift and Rossi X-ray Timing Explorer (RXTE) satellites, astronomers have discovered one of the most bizarre planet-mass objects ever found. The object's minimum mass is only about 7 times the mass of Jupiter. But instead of orbiting a normal star, this low-mass body orbits a rapidly spinning pulsar. It orbits the pulsar every 54.7 minutes at an average distance of only about 230,000 miles (slightly less than the Earth-Moon distance). "This object is merely the skeleton of a...

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2007-08-27 08:20:57

The chemical fingerprint of a burned-out star indicates that Earth-like planets may not be rare in the universe and could give clues to what our solar system will look like when our sun dies and becomes a white dwarf star some five billion years from now. Astronomers from UCLA report that a white dwarf star known as GD 362, which is surrounded by dusty rings similar to those of Saturn, has been contaminated by a large asteroid that left more than a dozen observable chemical elements in the...

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2007-07-13 08:40:00

VLT Provides Evidence for Type Ia Supernovae Scenario A unique set of observations, obtained with ESO's VLT, has allowed astronomers to find direct evidence for the material that surrounded a star before it exploded as a Type Ia supernova. This strongly supports the scenario in which the explosion occurred in a system where a white dwarf is fed by a red giant. Because Type Ia supernovae are extremely luminous and quite similar to one another, these exploding events have been used extensively...

e29c40d6f762e84821230e1cbe2b27941
2007-05-22 12:35:00

Andromeda, the nearest major galaxy to the Milky Way, is shown here in this wide-field optical image from Kitt Peak. The central region of Andromeda is shown in a composite image, with X-rays from NASA's Chandra X-ray Observatory (blue) combined with the optical image. Astronomers believe that Andromeda, also known as Andromeda Galaxy (M31), and the Milky Way will merge in a few billion years. In the composite image, hot, X-ray bright gas is seen to envelop the central region of Andromeda....

816cb904f8ffa85c8bc6f1f557bca1141
2007-05-09 09:06:08

ESA's X-ray observatory XMM-Newton has revealed a new class of exploding stars "“ where the X-ray emission "Ëœlives fast and dies young'. The identification of this particular class of explosions gives astronomers a valuable new constraint to help them model and understand stellar explosions. Exploding stars called novae remain a puzzle to astronomers. "Modelling these outbursts is very difficult," says Wolfgang Pietsch of the Max Planck Institut fr Extraterrestrische Physik....

40c8fcb87e21d8767b4dbe98a1d924631
2007-04-17 17:35:00

An Anglo-American team of astronomers have used the Advanced Camera for Surveys on the Hubble Space Telescope (HST) to obtain the first direct optical images of the aftermath of a recent titanic explosion that took place in a star system 5,000 light years from Earth. In a talk on Tuesday 17 April at the Royal Astronomical Society National Astronomy Meeting in Preston, Professor Michael Bode of Liverpool John Moores University will describe how these unique observations shed new light on the...

912c15ac17644e14814bdb771637b6631
2007-04-17 10:45:00

Cambridge, MA - Astronomers have found the lowest mass white dwarf known in our galaxy: a Saturn-sized ball of helium containing only about one-fifth the mass of the Sun. In addition, they have spotted the source of the white dwarf's radical weight-loss plan. An unseen companion, likely another white dwarf, has sucked away much of the tiny white dwarf's material, leaving it a shadow of its former self. "This star is bizarre," said Warren Brown of the Harvard-Smithsonian Center for...


Latest White dwarf Reference Libraries

6_c21be0ecb1b565a9be109a383c38223f2
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...

6_19859ff34fd03d00777232e2520ce83f4
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...

6_f1577ee462b741c03ef6a7d23d2cd6904
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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  • Color; hue; complexion.
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