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Latest Stellar evolution Stories

Nature's Constants Not Constant
2013-07-05 08:29:31

Lee Rannals for redOrbit.com - Your Universe Online An international team of astronomers wrote in the journal Physical Review Letters they were able to test a controversial theory about the constants of nature. The team studied a distant white dwarf star using the Hubble Space Telescope to measure the strength of the electromagnetic force, or alpha, one of the four fundamental forces that shape the universe as we know it. The researchers hoped to determine whether the laws of physics...

Stellar Collision Survivor New Type Pulsating Star
2013-06-28 14:54:18

Lee Rannals for redOrbit.com - Your Universe Online Astronomers have discovered that the brightness of the remnant of a stellar collision can vary in a way that scientists have not observed before. The team wrote in the journal Nature that these observations will allow astronomers to learn what happens when stars collide in binary systems. Stars like our Sun expand to become red giant stars when the hydrogen that fuels the nuclear fusion in their cores runs out. Binary stars will...

Computer Simulations Shed New Light On Neutron Star Formation
2013-06-28 04:30:08

redOrbit Staff & Wire Reports - Your Universe Online Researchers from the Max Planck Institute for Astrophysics (MPA) have, for the first time, created three-dimensional computer models in order to study the formation of neutron stars at the center of collapsing stars, officials from the German research center announced earlier this week. By creating what they call the most expensive and elaborate computer simulations of the process to date, the team of investigators confirmed,...

Spiral Galaxies Larger Than Thought
2013-06-27 13:50:10

Lee Rannals for redOrbit.com - Your Universe Online Astronomers now say spiral galaxies like the Milky Way galaxy are actually larger than previously thought. Scientists from several universities used the Hubble Space Telescope to determine that normal spiral galaxies are surrounded by halos of gas that can extend to over one million light-years in diameter. With this new estimate, it brings the Milky Way from just 100,000 light-years across to roughly 1,100,000 light-years. The...

Chandra Discovers Supernova Remnant Emission Is Synchrotron Radiation
2013-06-26 16:32:40

Lee Rannals for redOrbit.com – Your Universe Online Astronomers will be reporting details about a supernova remnant known as G1.9+0.3 in the upcoming issue of The Astrophysical Journal Letters. In 2008, a team of scientists discovered the remains of a supernova known to have occurred in the Milky Way, about 28,000 light years away from Earth. The explosion would have been visible from Earth a little more than a hundred years ago, assuming it was not obscured by dust and gas....

Supernova Gold Standard For Normal
2013-06-19 13:37:32

Lee Rannals for redOrbit.com - Your Universe Online A group of astronomers has released a dataset based on 32 nights of repeated observations of supernova 2011fe, creating a "gold-standard" atlas for Type 1a supernovae. Astronomers were able to catch supernova 2011fe just 12 hours after it exploded in the Pinwheel Galaxy in the Big Dipper. The supernova is easy to spot with binoculars, and has been nicknamed the Backyard Supernova. Researchers from the international Nearby Supernova...

Supernova Light Echo Detected
2013-06-05 13:28:46

Lee Rannals for redOrbit.com - Your Universe Online Astronomers discovered light echoing off of material surrounding a recent supernova explosion, supporting the theory that exploding white dwarfs become unstable from matter donated by large non-degenerate stars. The team detected the light echo coming off of SN 2009ig, making it the sixth and most luminous discovered from a type Ia supernova. A light echo works similarly in principle to the more familiar sound echoes heard on Earth....

Hubble Helps Astronomers Map Ejected Supernova Material In 3D
2013-06-04 12:22:13

Lee Rannals for redOrbit.com — Your Universe Online Astronomers using NASA's Hubble Space Telescope have mapped out a 3D structure of material ejected from an exploding star. The team used the space observatory to look at the light emitted by the close double-star system T-Pyxidis, which is a recurring nova. A nova erupts when a white dwarf has siphoned off enough hydrogen from a companion star to trigger a thermonuclear runaway. As the gas builds up on the surface of the star,...

Predicting The End Of Stars Relies On How Much Sodium They Have
2013-05-29 12:58:12

[WATCH VIDEOS: A Close Look At NGC 6752 | Zooming In On NGC 6752] Lee Rannals for redOrbit.com — Your Universe Online An international team of astronomers published a paper today in the journal Nature detailing the role sodium plays in determining how stars evolve and how they end their lives. Astronomers believe that stars like the Sun will blow off much of their atmospheres into space near the ends of their lives, which is known as asymptotic giant branch (AGB). However, new...


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...

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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...

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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...

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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...

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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...

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Word of the Day
grass-comber
  • A landsman who is making his first voyage at sea; a novice who enters naval service from rural life.
According to the OED, a grass-comber is also 'a sailor's term for one who has been a farm-labourer.'