Latest White dwarf Stories

Supernova Was Caused By A Yellow Supergiant
2012-09-29 06:47:07

redOrbit Staff & Wire Reports - Your Universe Online A team of Japanese researchers has discovered evidence that a yellow supergiant (YSG) was, in fact, the progenitor for a recently discovered supernova -- a discovery which they say raises serious questions regarding our understanding of the evolution of massive stars. Melina Bersten of the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) and colleagues analyzed evidence and discovered that supernova...

Supernova Cause Revealed A Millennium Later
2012-09-28 10:32:37

April Flowers for redOrbit.com - Your Universe Online Just over 1,000 years ago, one of the brightest stellar events ever recorded in history occurred. Between April 30 and May 1, 1006, a supernova was widely observed by a number of civilizations across the globe. Now, more than a thousand years later, a research team led by the University of Barcelona, the Instituto de Astrofisica de Canarias (IAC) and the Instituto de Ciencia de Materiales de Madrid (CSIC) has determined that SN 1006 was...

Searching For Supernova Progenitors
2012-08-04 06:23:15

Lee Rannals for redOrbit.com - Your Universe Online A progenitor of a type 1a supernova may have been found, according to findings published in the journal Monthly Notices of the Royal Astronomical Society. Astronomers believe that type 1a supernovae are thermonuclear explosions of a white dwarf star that is part of a binary system, which is two stars that are physically close and orbit a common center of mass. The white dwarf has mass gradually given to it by its companion star, and...

Wide-field view of the Andromeda Galaxy
2012-06-02 08:41:25

Unfortunately, stars don't have birth certificates. So, astronomers have a tough time figuring out their ages. Knowing a star's age is critical for understanding how our Milky Way galaxy built itself up over billions of years from smaller galaxies. Jason Kalirai of the Space Telescope Science Institute and The Johns Hopkins University's Center for Astrophysical Sciences, both in Baltimore, Md., has found the next best thing to a star's birth certificate. Using a new technique, Kalirai...

Two Different Sources for Supernova, Both Models Are Correct
2012-05-07 10:40:40

The exploding stars known as Type Ia supernovae serve an important role in measuring the universe, and were used to discover the existence of dark energy. They're bright enough to see across large distances, and similar enough to act as a "standard candle" - an object of known luminosity. The 2011 Nobel Prize in Physics was awarded for the discovery of the accelerating universe using Type Ia supernovae. However, an embarrassing fact is that astronomers still don't know what star systems make...

Image 1 - Exoplanet-Consuming White Dwarf Stars Discovered
2012-05-03 10:19:16

Astrophysicists at a UK university have found a quartet of white dwarf stars which they say are in the process of consuming exoplanets that were once similar in composition to Earth. According to a Thursday press release, researchers from the University of Warwick said that the four stars which they observed were surrounded by dust from shattered planetary bodies. They used the Hubble Space Telescope to survey the chemical composition of those stars' atmospheres, and discovered that the...

2012-04-13 03:26:20

A University of Oklahoma assistant professor and colleagues have identified two white dwarf stars considered the oldest and closest known to man.  Astronomers identified these 11- to 12-billion-year-old white dwarf stars only 100 light years away from Earth.  These stars are the closest known examples of the oldest stars in the Universe forming soon after the Big Bang, according to the OU researcher. Mukremin Kilic, assistant professor of physics and astronomy in the OU College...

Image 1 - Astrophysicists Gain Insight Into Star Creation From NASA Satellite
2012-03-21 07:47:08

NASA's Swift satellite puts faraway stars and galaxies under a new lens. A combination of X-ray and ultraviolet observations from NASA's Swift satellite allow researchers to gain a more detailed look at specific stars and their activities. Most recently Swift was used to study a Type Ia supernova. While it's been known that Type Ia supernovae originate with a remnant star called a white dwarf, the X-ray and ultraviolet views allow researchers to view the events and matter that cause the...

Image 1 - Important Clue Uncovered For Origins Of A Type Of Supernovae Explosion
2012-03-04 06:11:31

Pitt team used Sloan Digital Sky Survey to determine that the merger of double white dwarfs is a plausible explanation for Type Ia supernovae The origin of an important type of exploding stars–Type Ia supernovae–have been discovered, thanks to a research team at the University of Pittsburgh. Studying supernovae of this type helps researchers measure galaxy distances and can lead to important astronomical discoveries. A paper detailing this research has been accepted for...

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
  • In music, a work for a keyboard-instrument, like the pianoforte or organ, originally intended to utilize and display varieties of touch: but the term has been extended so as to include many irregular works, similar to the prelude, the fantasia, and the improvisation.
This word is Italian in origin, coming from the feminine past participle of 'toccare,' to touch.