Quantcast

Latest Stellar evolution Stories

633fcc16a62798b8f9c889f249130fdd1
2009-12-15 07:43:39

Dying, for stars, has just gotten more complicated. For some stellar objects, the final phase before or instead of collapsing into a black hole may be what a group of physicists is calling an electroweak star. Glenn Starkman, a professor of physics at Case Western Reserve University, together with former graduate students and post-docs De-Chang Dai and Dejan Stojkovic, now at the State University of New York in Buffalo, and Arthur Lue, at MIT's Lincoln Lab, offer a description of the...

7fedbadc344b66b5b2e0ca8ff274f1531
2009-11-17 08:20:00

Astronomers find prime suspect for a Type Ia supernova Using ESO's Very Large Telescope and its ability to obtain images as sharp as if taken from space, astronomers have made the first time-lapse movie of a rather unusual shell ejected by a "vampire star", which in November 2000 underwent an outburst after gulping down part of its companion's matter. This enabled astronomers to determine the distance and intrinsic brightness of the outbursting object. It appears that this double star system...

bfbe1f32fd16a2ec3f1cd51aef9bdc66
2009-11-12 14:19:47

Astrophysicists find 2 Earth-sized bodies with oxygen rich atmospheres - only snag is they're stars not planets Astrophysicists at the University of Warwick and Kiel University have discovered two earth sized bodies with oxygen rich atmospheres "“ however there is a bit of a disappointing snag for anyone looking for a potential home for alien life, or even a future home for ourselves, as they are not planets but are actually two unusual white dwarf stars. The two white dwarf stars SDSS...

6fb43401526336ec41c6b991508d39a0
2009-11-05 13:35:00

A new class of supernova was discovered by scientists at Berkeley and may be the first example of a new type of exploding star. A team of astrophysicists at UC Santa Barbara had predicted this kind of explosion in their theoretical work. Lars Bildsten, professor at UCSB's Kavli Institute for Theoretical Physics (KITP), and colleagues, predicted a new type of supernova in distant galaxies that would be fainter than most and would rise and fall in brightness in only a few weeks. The discovery,...

c9c24e628372e33889b6abb67d8384a1
2009-11-05 06:55:00

Evidence for a thin veil of carbon has been found on the neutron star in the Cassiopeia A supernova remnant. This discovery, made with NASA's Chandra X-ray Observatory, resolves a ten-year mystery surrounding this object. "The compact star at the center of this famous supernova remnant has been an enigma since its discovery," said Wynn Ho of the University of Southampton and lead author of a paper that appears in the latest issue of Nature. "Now we finally understand that it can be produced...

51e33853898b1455940fdf807bde65d71
2009-09-22 15:25:00

The precise conditions inside a white dwarf star in the hours leading up to its explosive end as a Type Ia supernova are one of the mysteries confronting astrophysicists studying these massive stellar explosions. But now, a team of researchers, composed of three applied mathematicians at the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory and two astrophysicists, has created the first full-star simulation of the hours preceding the largest thermonuclear explosions in...

9a6b75521c978a9f454d814749516b97
2009-09-03 13:35:00

ESA's XMM-Newton orbiting X-ray telescope has uncovered a celestial Rosetta stone: the first close-up of a white dwarf star, circling a companion star, that could explode into a particular kind of supernova in a few million years. These supernovae are used as beacons to measure cosmic distances and ultimately understand the expansion of our Universe. Astronomers have been on the trail of this mysterious object since 1997, when they discovered that something was giving off X-rays near the...

a9ede21b18833952f95c14b0412ccace1
2009-08-19 14:05:00

For decades, astronomers have gone about their business of studying the cosmos with the assumption that stars of certain sizes form in certain quantities. Like grocery stores selling melons alone, and blueberries in bags of dozens or more, the universe was thought to create stars in specific bundles. In other words, the proportion of small to big stars was thought to be fixed. For every star 20 or more times as massive as the sun, for example, there should be 500 stars with the sun's mass or...

1841aa3ada216dec52048edaac20265d1
2009-08-14 07:35:00

A team of scientists in Australia and the United States, led by Associate Professor Miroslav FilipoviÄ“¡ from the University of Western Sydney, have discovered a new class of object which they call "Super Planetary Nebulae."  They report their work in the journal Monthly Notices of the Royal Astronomical Society. Planetary nebulae are shells of gas and dust expelled by stars near the end of their lives and are typically seen around stars comparable or smaller in...

2009-08-12 12:42:02

The stellar explosions known as type 1a supernovae have long been used as "standard candles," their uniform brightness giving astronomers a way to measure cosmic distances and the expansion of the universe. But a new study published this week in Nature reveals sources of variability in type 1a supernovae that will have to be taken into account if astronomers are to use them for more precise measurements in the future.The discovery of dark energy, a mysterious force that is accelerating the...


Latest Stellar evolution Reference Libraries

Stellar Astrophysics
2014-01-12 00:00:00

The prominent feature that allows for the existence of life on Earth is the Sun. Radiation from our closest star provides heat and energy to our planet, driving biological processes and providing the necessary conditions for liquid water to naturally exist. But our Sun is only but one star in this vast Universe. And as it turns out, most stars are quite different than the one that illuminates our day. For this reason, scientists have, for hundreds of years, attempted to study the other...

7_4b235c0bfbfc8504a41844f9c48ad8962
2004-10-19 04:45:43

Hertzsprung-Russell Diagram -- In stellar astronomy, the Hertzsprung-Russell diagram (H-R diagram) shows the relation between the absolute magnitude and the spectral types of stars. It was invented around 1910 by Ejnar Hertzsprung and Henry Norris Russell. There are two equivalent forms. One is the observer's form which plots the color of the star on one axis and the absolute magnitude on the other axis. The theoretician's form plots the temperature of the star on one axis and the...

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_19859ff34fd03d00777232e2520ce83f5
2004-10-19 04:45:42

Supernova Remnant -- A supernova remnant (SNR) is made up of the materials left behind by the gigantic explosion of a star in a supernova. There are two possible routes to this end: either a massive star may cease to generate fusion energy in its core, and collapse inward under the force of its own gravity, or a white dwarf star may accumulate material from a companion star until it reaches a critical mass and undergoes a similar collapse. In either case, the resulting supernova...

6_79c799b9f03f60809a9d0aecf38491202
2004-10-19 04:45:42

Supernova -- A supernova is a star that increases its brightness drastically within a matter of days, making it appear as if a "new" star was born (hence "nova"). The "super" prefix distinguishes it from a mere nova, which also involves a star increasing in brightness, though to a lesser extent and through a much different mechanism. Astronomers have classified supernovae in several classes, according to the lines of different elements that appear in their spectra. The first...

More Articles (13 articles) »
Word of the Day
omadhaun
  • A fool; a simpleton: a term of abuse common in Ireland and to a less extent in the Gaelic-speaking parts of Scotland.
This word is partly Irish in origin.