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Latest White dwarf Stories

c436f6672e4d655a32ebfdfe239207391
2009-04-24 08:15:00

Twenty-four unusual stars, 18 of them newly discovered, have been observed in new Hubble telescope images. The stars are white dwarfs, a common type of dead star, but they are odd because they are made of helium rather than the usual carbon and oxygen. This is the first extensive sequence of helium-core white dwarfs to be observed in a globular cluster, a dense swarm of some of the oldest stars in our galaxy. A study, accepted for publication in the Astrophysical Journal, suggests that these...

96d0717d3faca4ce54c3f7748ccd371a1
2009-04-23 09:45:00

Researchers at North Carolina State University have used a mathematical model that allows them to get a clearer picture of the galaxy's youngest supernova remnant by correcting for the distortions caused by cosmic dust. Their new data provides evidence that this remnant is from a type Ia supernova - the explosion of a white dwarf star - and raises questions about the ways in which magnetic fields affect the generation of the remnant's cosmic ray particles. NC State physicists Dr. Stephen...

2e968f6c8dab0921c1f6a983cad10ea11
2009-04-22 09:29:43

Astronomers have found three brown dwarfs with estimated masses of less than 10 times that of Jupiter, making them among the youngest and lowest mass sub-stellar objects detected in the solar neighborhood to date. The observations were made by a team of astronomers working at the Laboratoire d'Astrophysique de l'Observatoire de Grenoble (LAOG), France, using the Canada-France-Hawaii Telescope (CFHT). Andrew Burgess will be presenting the discovery at the European Week of Astronomy and Space...

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2009-04-22 06:40:00

Using the NASA / ESA Hubble Space Telescope (HST), an international team of astronomers have taken the first optical images of a dramatic stellar outburst and discovered a peanut-shaped bubble expanding rapidly into space. Team member Valerio Ribeiro, a graduate student from Liverpool John Moores University will present their results on Wednesday 22nd April at the European Week of Astronomy and Space Science conference at the University of Hertfordshire. The scientists looked at a star in the...

3384de13265db4191fbec7631362fe5f1
2009-04-14 10:15:00

Scientists have developed a new explanation for how youthful type Ia supernovae are formed. Dr. Bo Wang and colleagues from the Yunnan Observatory of the Chinese Academy of Sciences created a new model that links the formation of type Ia supernovae to the transfer of a material from a helium star to a white dwarf companion. White dwarves are dense remnants of stars like the Sun. Scientists theorize that these white dwarves borrow matter from a nearby star. Once the mass of the remnant star...

d6f824f3f0ba1d5b2f328d6a4775575d
2009-04-08 09:45:00

A team of astronomers, led by Dr. Bo Wang from the Yunnan Observatory of the Chinese Academy of Sciences, have developed a new model which explains the formation of the most youthful type Ia supernovae. In a paper published in Monthly Notices of the Royal Astronomical Society, Dr. Bo Wang and his team show how the transfer of material from a "Ëœhelium star' to a compact white dwarf companion causes these cataclysmic events to take place early on in the life of the galaxy they formed...

0e7c89b74e61f5abb235e8963d0fe182
2009-01-05 13:20:00

Astronomers have turned to an unexpected place to study the evolution of planets -- dead stars. Observations made with NASA's Spitzer Space Telescope reveal six dead "white dwarf" stars littered with the remains of shredded asteroids. This might sound pretty bleak, but it turns out the chewed-up asteroids are teaching astronomers about the building materials of planets around other stars. So far, the results suggest that the same materials that make up Earth and our solar system's other rocky...

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2008-12-12 12:45:00

Astronomy & Astrophysics is publishing spectroscopic observations with NASA's space-based Far-Ultraviolet Spectroscopic Explorer (FUSE) of the white dwarf KPD 0005+5106. The team of German and American astronomers who present these observations show that this white dwarf is among the hottest stars known so far, with a temperature of 200 000 K at its surface. It is so hot that its photosphere exhibits emission lines in the ultraviolet spectrum, a phenomenon that has never been seen before....

2008-12-11 12:28:46

U.S. space agency officials say the Spitzer Space Telescope has discovered the dimmest known star-like objects in the universe. The record goes to twin brown dwarfs, or failed stars, each of which shines with only one-millionth the light of our sun, the National Aeronautics and Space Administration said. Astronomers previously thought the faint image was that of just one brown dwarf. But when the Spitzer Space Telescope observed the object in infrared mode, it measured the extreme faintness...

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2008-07-18 09:05:00

XMM-Newton has discovered an exploding star in the Milky Way. Usually that would be important in itself, but this time there is a special twist. Calculations show that the explosion must have been clearly visible to the unaided eye but was missed by the legions of star watchers around the planet. On October 9, 2007, ESA's orbiting X-ray observatory XMM-Newton was turning from one target to another. As it did so, it passed across a bright source of X-rays that no one was expecting. The source...


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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