Nothing lights up the cosmos like a supernova
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Publicado: 2 de noviembre de 2010
Source: www.discoverychannel.com
Nothing lights up the cosmos like a Supernova
When a star dies by an explosion, it releases great amounts of mass and energy. Since thistype of explosion rarely happens, astronomers classify them into two types: type Ia supernovae and type II supernovae.
Type II supernovae:
When a star collapses, the star’smass has a gravity pull towards the inside, which tries to expand the star, while nuclear fusion reactions have an outward push of pressure, this one tries to crush it.Mario Livio, an astrophycist, says that stars spend their life fusing different elements to transform them into heavier elements. But eventually a star’s core turns into iron andwith no outward forces it collapses. The core breaks down because its temperature rises due to an immense pressure that breaks its iron nuclei. The core breaks into enormousdensity at that point a bounce occurs, and the core becomes too hard to squeeze. The bounce is like a shock wave, it expands through the entire steller envelope, which isseveral solar masses worth of material that surrounds the core. It blasts away at a speed of ten thousand miles per second.
What’s left of the core may form two things: a blackhole or a neutron star which is a super dense object that spans about 10 kilometers.
Type Ia:
These type of explosions only occur with white dwarfs, which are stars that haveabout the same mass as the sun and its radius is just like Earth’s. Stars like these cannot have a mass higher than 1.4 times the mass of the sun, otherwise they can’t holdthemselves against gravity. The star can get to that amount of mass by merging or growing its material with another white dwarf and if this happens, the white dwarf explodes.
Nothing lights up the cosmos like a Supernova
When a star dies by an explosion, it releases great amounts of mass and energy. Since thistype of explosion rarely happens, astronomers classify them into two types: type Ia supernovae and type II supernovae.
Type II supernovae:
When a star collapses, the star’smass has a gravity pull towards the inside, which tries to expand the star, while nuclear fusion reactions have an outward push of pressure, this one tries to crush it.Mario Livio, an astrophycist, says that stars spend their life fusing different elements to transform them into heavier elements. But eventually a star’s core turns into iron andwith no outward forces it collapses. The core breaks down because its temperature rises due to an immense pressure that breaks its iron nuclei. The core breaks into enormousdensity at that point a bounce occurs, and the core becomes too hard to squeeze. The bounce is like a shock wave, it expands through the entire steller envelope, which isseveral solar masses worth of material that surrounds the core. It blasts away at a speed of ten thousand miles per second.
What’s left of the core may form two things: a blackhole or a neutron star which is a super dense object that spans about 10 kilometers.
Type Ia:
These type of explosions only occur with white dwarfs, which are stars that haveabout the same mass as the sun and its radius is just like Earth’s. Stars like these cannot have a mass higher than 1.4 times the mass of the sun, otherwise they can’t holdthemselves against gravity. The star can get to that amount of mass by merging or growing its material with another white dwarf and if this happens, the white dwarf explodes.
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