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===Neutron Star=== | ===Neutron Star=== | ||
Usually type B-0 and measures only a few kilometres in diametre. An early main sequence star that has completed the nuclear burning processes often explodes. The reactive force of the explosion and the | Usually type B-0 and measures only a few kilometres in diametre. An early main sequence star that has completed the nuclear burning processes often explodes. The reactive force of the explosion and the star's self-gravitation eject shell electrons (as in a white dwarf) and nuclear positrons. This leaves a neutroneum core, possibly covered by a thin degenerate matter shell. | ||
===Population I=== | ===Population I=== | ||
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===Red Giant Star=== | ===Red Giant Star=== | ||
The red giant phase is common in the evolution of many less massive stars. When core hydrogen is exhausted, gravitational collapse ignites hydrogen shell burning outside the core. The | The red giant phase is common in the evolution of many less massive stars. When core hydrogen is exhausted, gravitational collapse ignites hydrogen shell burning outside the core. The star's envelope expands far beyond the photosphere limit. The star's atmosphere is relatively cool. | ||
===Runaway Star=== | ===Runaway Star=== | ||
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===Supernova=== | ===Supernova=== | ||
When a massive young star exhausts its core hydrogen it undergoes second-stage gravitational collapse. The resulting core temperature increase leads to runaway nuclear burning of helium, carbon, nitrogen and an explosion that blasts the | When a massive young star exhausts its core hydrogen it undergoes second-stage gravitational collapse. The resulting core temperature increase leads to runaway nuclear burning of helium, carbon, nitrogen and an explosion that blasts the star's outer layer into space. Supernova explosions are the major source of metals and other galactic elements. | ||
===T Tauri Star=== | ===T Tauri Star=== | ||
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===White Dwarfs=== | ===White Dwarfs=== | ||
Primarily degenerate matter, this main sequence star, usually of type G-late A, has completed nuclear burning processes and has collapsed into a configuration roughly the size of a small planet. White dwarfs radiate at various levels of intensity through self-gravitational collapse. Nuclear burning occurs only on the surface through accretion of unburned matter from other sources; in such cases, nuclear ignition can regularily occure and is the source of the | Primarily degenerate matter, this main sequence star, usually of type G-late A, has completed nuclear burning processes and has collapsed into a configuration roughly the size of a small planet. White dwarfs radiate at various levels of intensity through self-gravitational collapse. Nuclear burning occurs only on the surface through accretion of unburned matter from other sources; in such cases, nuclear ignition can regularily occure and is the source of the "recurrent nova" effect. The spectral class of white dwarf stars is usually prefixed with a 'D'. | ||
==Spectral Types== | ==Spectral Types== | ||
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Stars at the '0' end of this band are hotter (around 50,000 degrees K); bluer in colour and more massive; those at the other end are cooler (around 2,000 degrees K), redder in colour and less massive. A conventional code for star colour is: | Stars at the '0' end of this band are hotter (around 50,000 degrees K); bluer in colour and more massive; those at the other end are cooler (around 2,000 degrees K), redder in colour and less massive. A conventional code for star colour is: | ||
* 0 | * 0 - Violet = White | ||
* B | * B - Blue = White | ||
* A - White | * A - White | ||
* F | * F - Yellow = White | ||
* G | * G - Yellow | ||
* K | * K - Orange | ||
* M | * M - Red | ||
While a 'Giant' star may have a radius of up to 1,000 times that of Sol and be up to 100,000 times as luminous, most of the stars are in the 'main sequence' portion of their lifetimes and have values near the typical main sequence ones for their type. Sol, | While a 'Giant' star may have a radius of up to 1,000 times that of Sol and be up to 100,000 times as luminous, most of the stars are in the 'main sequence' portion of their lifetimes and have values near the typical main sequence ones for their type. Sol, Earth's sun, is a type G. Its spectrum, as filtered by Earth's atmosphere, is the basis for standard illumination in Human quarters. | ||
===Type 0 : (Violet-White)=== | ===Type 0 : (Violet-White)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 30,000 - 50, | * '''Temperature''': 30,000 - 50,000 K | ||
* '''Mass''': 10 - 30 Solar Masses | * '''Mass''': 10 - 30 Solar Masses | ||
* '''Radius''': 2.5 - 3.0 Solar Radii | * '''Radius''': 2.5 - 3.0 Solar Radii | ||
* '''Luminosity''': 1,000 | * '''Luminosity''': 1,000 - 100,000 SOL | ||
=== Type B: (Blue-White)=== | === Type B: (Blue-White)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 10,000 | * '''Temperature''': 10,000 - 30,000 K | ||
* '''Mass''': 3-5 Solar Masses | * '''Mass''': 3-5 Solar Masses | ||
* '''Radius''': 2.0 | * '''Radius''': 2.0 - 3.5 Solar Radii | ||
* '''Luminosity''': 10 | * '''Luminosity''': 10 - 1,000 SOL | ||
===Type A: (White)=== | ===Type A: (White)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 7,500 | * '''Temperature''': 7,500 - 10,000 K | ||
* '''Mass''': 2 | * '''Mass''': 2 - 3 Solar Masses | ||
* '''Radius''': 1.5 | * '''Radius''': 1.5 - 2.0 Solar Radii | ||
* '''Luminosity''': 5 | * '''Luminosity''': 5 - 10 SOL | ||
===Type F: (Yellow | ===Type F: (Yellow - White)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 6,000 | * '''Temperature''': 6,000 - 7,500 K | ||
* '''Mass''': 1 | * '''Mass''': 1 - 2 Solar Masses | ||
* '''Radius''': 1.0 | * '''Radius''': 1.0 - 1.5 Solar Radii | ||
* '''Luminosity''': 1 | * '''Luminosity''': 1 - 5 SOL | ||
===Type G: (Yellow)=== | ===Type G: (Yellow)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 4,500 | * '''Temperature''': 4,500 - 6,000 K | ||
* '''Mass''': 8 | * '''Mass''': 0.8 - 1 Solar Masses | ||
* '''Radius''': 0.8 | * '''Radius''': 0.8 - 1.0 Solar Radii | ||
* '''Luminosity''': 0.1 | * '''Luminosity''': 0.1 - 1 SOL | ||
===Type K: (Orange)=== | ===Type K: (Orange)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 3,500 | * '''Temperature''': 3,500 - 4,500 K | ||
* '''Mass''': 0.5 | * '''Mass''': 0.5 - 0.8 Solar Masses | ||
* '''Radius''': 0.5 | * '''Radius''': 0.5 - 0.8 Solar Radii | ||
* '''Luminosity''': 0.01 | * '''Luminosity''': 0.01 - 0.1 SOL | ||
===Type M: (Red)=== | ===Type M: (Red)=== | ||
Main Sequence Value Ranges: (Approximate) | Main Sequence Value Ranges: (Approximate) | ||
* '''Temperature''': 2,000 | * '''Temperature''': 2,000 - 3,500 K | ||
* '''Mass''': 0.02 | * '''Mass''': 0.02 - 0.5 Solar Masses | ||
* '''Radius''': 0.01 | * '''Radius''': 0.01 - 0.5 Solar Radii | ||
* '''Luminosity''': 0.00001 | * '''Luminosity''': 0.00001 - 0.01 SOL | ||
''This article was supplied by Starwind RPG.'' | ''This article was supplied by Starwind RPG.'' | ||
[[Category:Science]] | [[Category:Science]] | ||
[[Category:Astronomy]] |
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