Latest White dwarf Stories

2009-07-01 13:56:42

An international team of astronomers using the European Space Agency's XMM-Newton X-ray observatory says it's discovered a new kind of black hole. The scientists, led by Sean Farrell of the University of Leicester, England, said the newly found black hole weighs more than 500 solar masses and is a missing link between lighter stellar-mass and heavier super-massive black holes. Stellar-mass black holes about 3 to 20 times as massive as the sun, and super-massive black holes several million to...

2009-06-10 15:17:49

In November 2008, Caroline Moore, a 14-year-old student from upstate New York, discovered a supernova in a nearby galaxy, making her the youngest person ever to do so. Additional observations determined that the object, called SN 2008ha, is a new type of stellar explosion, 1000 times more powerful than a nova but 1000 times less powerful than a supernova. Astronomers say that it may be the weakest supernova ever seen. Even though this explosion was a weakling compared to most supernovae, for...

2009-06-09 10:57:27

In a controversial new paper in the journal Nature, astronomers from Queen's University Belfast have proposed a new physical interpretation of a supernova discovered on 7th November 2008.A group of researchers, led by Dr. Stefano Valenti from Queen's University Belfast, found a weak explosion that is unusual in many ways, and several lines of evidence suggest it could be from a massive star.This goes against mainstream thinking in the astrophysics community which believes that this type of...

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...

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...

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...

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...

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...

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...

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...

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
  • A Roman unit of weight, 1⁄1728 of a pound.
  • A weight of four grains used in weighing gold and precious stones; a carat.
  • In anatomy, a formation suggesting a husk or pod.
  • The lowest unit in the Roman coinage, the twenty-fourth part of a solidus.
  • A coin of base silver of the Gothic and Lombard kings of Italy.
'Siliqua' comes from a Latin word meaning 'a pod.'