Latest White dwarf Stories
April Flowers for redOrbit.com - Your Universe Online NASA's Chandra X-ray Observatory has identified the cause of Kepler's supernova, the famous explosion first discovered by Johannes Kepler in 1604. The image above shows low (red), intermediate (green) and high (blue) energy X-rays with a star field background from the Digitized Sky Survey. It is already known that the supernova is a Type Ia, which is the thermonuclear explosion of a white dwarf star. Type Ia's are important cosmic...
North Carolina State University Life as we know it is based upon the elements of carbon and oxygen. Now a team of physicists, including one from North Carolina State University, is looking at the conditions necessary to the formation of those two elements in the universe. They’ve found that when it comes to supporting life, the universe leaves very little margin for error. Both carbon and oxygen are produced when helium burns inside of giant red stars. Carbon-12, an essential element...
John P. Millis, PhD for redOrbit.com – Your Universe Online Astronomers have long been aware of supernovae – brilliant explosions ejecting massive amounts of gas and energy into the surrounding medium. But occasionally one of them is different, set apart, unlike anything we have seen before. Researchers with the Harvard-Smithsonian Center for Astrophysics (CfA) have announced in a new paper that one such event has been discovered. Supernovae are split into sub-types. While some...
Lee Rannals for redOrbit.com – Your Universe Online White dwarf supernovae that occurred millions of years ago have popped up in the Virgo Cluster galaxy and part of the sky labelled as "anonymous." Southern Methodist University (SMU) researchers say they've confirmed two bright stars that showed up in our skies in February and November are supernovae. Supernovae are the result of stars that have reached the end of their life, resulting in a large explosion that can consume anything...
April Flowers for redOrbit.com - Your Universe Online There are small subsets of stars among the hundred billion in the Milky Way called ultra-cool dwarfs, which have a temperature below 2500 Kelvin. Both ultra-cool dwarfs and brown dwarfs exist at these lower temperatures. The lower temperatures indicate that these are some of the most ancient objects in our Galaxy, leading scientists to examine them for information on primitive chemical composition. The Gaia mission, which will be...
WASHINGTON, Jan. 8, 2013 /PRNewswire-USNewswire/ -- Astronomers using NASA's Spitzer and Hubble space telescopes have probed the stormy atmosphere of a brown dwarf, creating the most detailed "weather map" yet for this class of cool, star-like orbs. The forecast shows wind-driven, planet-sized clouds enshrouding these strange worlds. (Logo: http://photos.prnewswire.com/prnh/20081007/38461LOGO) Brown dwarfs form out of condensing gas, as stars do, but lack the mass to fuse...
Lee Rannals for redOrbit.com – Your Universe Online University of Southampton researchers reported in The Astrophysical Journal that they have observed bright X-ray flares in a nearby galaxy being produced by a white dwarf. The team made the discovery by detecting a dramatic, short-lived X-ray flare that was picked up by an X-ray telescope on the International Space Station (ISS). Astronomers used optical telescopes in South Africa and Chile to help observe the flare, called...
Lee Rannals for redOrbit.com - Your Universe Online - Video 1 | Video 2 | Video 3 Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that the outer region of a dusty disc encircling a brown dwarf contains solid grains like those found in denser discs of newborn stars. The find challenges theories of how rock, Earth-scale planets form, suggesting the planets may be more common in the Universe than expected. Scientists believe rocky planets form...
April Flowers for redOrbit.com - Your Universe Online A type of oddly dim exploding star is probably a class of duds, a new study using supercomputer simulations finds, but one that could throw new light on the mysterious nature of dark energy. Thousands of exploding stars are classified as type Ia supernovae, and most of them look similar to each other. This is why astrophysicists use them as accurate cosmic distance indicators, they show that the expansion of the universe is...
[ Video 1 ] | [ Video 2 ] | Video 3 ] Lee Rannals for redOrbit.com - Your Universe Online Astronomers have discovered a pair of stars orbiting each other at the center of a remarkable example of a planetary nebula. The latest find confirms a theory about what controls the spectacular and symmetric appearance of the material flung out into space. Planetary nebulae are glowing shells of gas around white dwarfs, and Fleming 1 is considered a great example that has strikingly...
Latest White dwarf Reference Libraries
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...
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...
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...
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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