Quantcast
Last updated on April 19, 2014 at 18:42 EDT

Latest White dwarf Stories

1e273da7c82b84e77e2129febe82ec47
2006-10-06 05:25:00

Scientists using NASA's Swift satellite have observed two dozen recent star explosions, called supernovae, quickly after the event and have discovered never-before-seen properties, some of which run counter to prevailing theories. In one observation, they have confirmed the origin of Type Ia supernovae, an important class of explosions used to measure distances and dark energy. In other observations they have found new mechanisms to produce X-rays and ultraviolet light. The findings have...

47d2e01eb88c98ede41b338f53ef67ed1
2006-09-12 12:00:00

"For the first time, we have clearly established a 'genetic difference' between stars in the disc and the bulge of our Galaxy," said Manuela Zoccali, lead author of the paper presenting the results in the journal Astronomy and Astrophysics [1]. "We infer from this that the bulge must have formed more rapidly than the disc, probably in less than a billion years and when the Universe was still very young." The Milky Way is a spiral galaxy, having pinwheel-shaped arms of gas, dust, and stars...

92f6a1327136984904c377c2bd0d58c21
2006-09-12 09:05:00

Galactic Bulge and Disc Stars Shown To Have Different Oxygen Abundances Looking in detail at the composition of stars with ESO's VLT, astronomers are providing a fresh look at the history of our home galaxy, the Milky Way. They reveal that the central part of our Galaxy formed not only very quickly but also independently of the rest. "For the first time, we have clearly established a 'genetic difference' between stars in the disc and the bulge of our Galaxy," said Manuela Zoccali, lead...

73c16bcd86dc7075d58a1ad15d2d96811
2006-08-17 12:45:18

NASA's Hubble Space Telescope has uncovered what astronomers are reporting as the dimmest stars ever seen in any globular star cluster. Globular clusters are spherical concentrations of hundreds of thousands of stars. These clusters formed early in the 13.7-billion-year-old universe. The cluster NGC 6397 is one of the closest globular star clusters to Earth. Seeing the whole range of stars in this area will yield insights into the age, origin, and evolution of the cluster. Although...

21ecb82f8b72f44761e9941196ae5da11
2006-08-04 12:31:51

Using ESO's Very Large Telescope, astronomers have discovered a rather unusual system, in which two planet-size stars, of different colours, orbit each other. One is a rather hot white dwarf, weighing a little bit less than half as much as the Sun. The other is a much cooler, 55 Jupiter-masses brown dwarf. "Such a system must have had a very troubled history", said Pierre Maxted, lead author of the paper that reports the study in this week's issue of Nature. "Its existence proves that the...

bf7d53c7d1c1cef68b930df14a8e46a51
2006-07-20 10:12:03

A team of astronomers from the UK and Germany have found that a nuclear explosion on the surface of a star 5,000 light years from Earth resulted in a blast wave moving at over 1,700 km per second. Dr. Richard Porcas from the Max Planck Institute for Radio Astronomy in Bonn coordinated the observations with the European VLBI network (EVN). The discovery, reported in the 20th July issue of Nature, was made by bringing together many of the world's radio telescopes into arrays capable of seeing...

afad44f008aad7cb848abd47bde1ddeb1
2006-04-07 06:30:00

On February 12, 2006, amateur astronomers reported that a faint star in the constellation of Ophiuchus had suddenly become clearly visible in the night sky without the aid of a telescope. Speaking today (Friday) at the RAS National Astronomy Meeting at Leicester, Professor Mike Bode of Liverpool John Moores University and Dr Tim O'Brien of Jodrell Bank Observatory will present the latest results which are shedding new light on what happens when stars explode. Records show that this so-called...

7d47e8abd64bfde646916aa7acec03cd1
2006-03-22 14:59:22

Arizona -- Astronomers have discovered a unique "brown dwarf" right in our solar neighborhood. If your city were the galaxy, it would be like finding someone you didn't know about living upstairs in your house, one of the discoverers said. The rare object is only 12.7 light years from Earth, circling a primary star that itself was discovered only recently in the southern hemisphere constellation Pavo (the Peacock). Only one other brown dwarf system has been found closer to Earth, and it's...

2006-03-15 20:20:00

NASHVILLE, Tenn. "“ Pity the brown dwarf. It's too large to be a planet, but too small to be a star. Although these "failed stars" are neither fish nor fowl, they play an important role in the cosmic scheme of things. Many astronomers think that they may actually be the most common product of the stellar formation process. So information about brown dwarfs can provide valuable new insights into the dynamic processes that produce stars out of collapsing whirlpools of interstellar dust...

6808057c60f2d4485470e25432fd8a441
2006-03-15 12:45:00

Hubble -- For the first time, astronomers have succeeded in weighing a binary pair of brown dwarfs and precisely measuring their diameters. These kinds of exact measurements are not possible when observing a single brown dwarf. Because their orbits are inclined edge-on to Earth, the dwarfs pass in front of each other, creating eclipses. This is the first brown dwarf-eclipsing binary ever discovered. The pair offers an unusual opportunity for accurately determining the masses and diameters of...


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...

More Articles (4 articles) »