what is a supernovae?

Answer 1

http://en.wikipedia.org/wiki/Supernova
this is wiki free encyclopedia check it out!!!

A supernova (plural: supernovae or supernovas) is a stellar explosion that creates an extremely luminous object that is initially made of plasma—an ionized form of matter.

There are several types of supernovae and at least two possible routes to their formation. A massive star may cease to generate energy from the nuclear fusion of atoms in its core, and collapse under the force of its own gravity to form a neutron star or black hole. Alternatively, a white dwarf star may accumulate material from a companion star (either through accretion or a collision) until it nears the Chandrasekhar limit of roughly 1.44 times the mass of the Sun, at which point it undergoes runaway nuclear fusion in its interior, completely disrupting the star. This second type of supernova is distinct from a surface thermonuclear explosion on a white dwarf, which is called a nova. Solitary stars with a mass below approximately 8 solar masses, such as the Sun itself, evolve into white dwarfs without ever becoming supernovae.

Answer 2

Supernova = singular
Supernovae = plural

A supernova is a stellar explosion that creates an extremely luminous object that is initially made of plasma—an ionized form of matter. A supernova may briefly out-shine its entire host galaxy before fading from view over several weeks or months. During this brief period of time, the supernova radiates as much energy as the Sun would emit over about 10 billion years. The explosion expels much or all of a star's material at a velocity of up to a tenth the speed of light, driving a shock wave into the surrounding interstellar gas. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant.

There are several types of supernovae and at least two possible routes to their formation. A massive star may cease to generate energy from the nuclear fusion of atoms in its core, and collapse under the force of its own gravity to form a neutron star or black hole. Alternatively, a white dwarf star may accumulate material from a companion star (either through accretion or a collision) until it nears the Chandrasekhar limit of roughly 1.44 times the mass of the Sun, at which point it undergoes runaway nuclear fusion in its interior, completely disrupting the star. This second type of supernova is distinct from a surface thermonuclear explosion on a white dwarf, which is called a nova. Solitary stars with a mass below approximately 8 solar masses, such as the Sun itself, evolve into white dwarfs without ever becoming supernovae.

On average, supernovae occur about once every 50 years in a galaxy the size of the Milky Way and play a significant role in enriching the interstellar medium with heavy elements. Furthermore, the expanding shock waves from supernova explosions can trigger the formation of new stars

Answer 3

There are actually two types of supernova, but I'll cover the most spectacular type first --

As you probably know, all stars live most of their lives in a constant struggle between heat and gravity. Gravity is constantly trying to make the star collapse in on itself, while at the same time the tremendous temperature of the star is trying to make it explode. As long as these two forces are in balance the star is stable. After billions of years, all stars run out of the hydrogen that fuels the nuclear furnace in their cores. Then the star will begin using the next heavier element (..helium)as fuel. This cycle of exhausting one fuel for another continues until finally the star has no fuel of any kind and the core cools. This means that at last gravity wins the tug-of-war. This will happen to our own sun in about 4.5-billion years. At that time gravity will squeeze the material of the sun into a sphere about the size of Earth and the sun will be what's known as a 'white dwarf' star. For stars that are at least 1.5 times more massive than our sun, the end result of running out of fuel is a lot different. When the star's core cools and gravity takes over, the entire mass of the star suddenly collapses in less than a second. The star material becomes highly compressed such that an awesome explosion takes place that we call a 'supernova.' Only the core of the original star remains and becomes so densely packed together that its atoms are compressed into neutrons. A 'neutron star' is formed. If the original star was at least 10 times more massive than our own sun, the core becomes so compacted and dense that its gravity prevents anything from ever escaping back into space--not even light. This is what we call a 'black hole.'

The second type of supernova (..type 1A) happens when a tiny white dwarf star is in orbit around a much larger star. Material from the larger star falls onto the surface of the white dwarf and accumulates. Over time, this accumulation becomes so great that an immense nuclear explosion takes place on the white dwarf surface.

Answer 4

Looks the first two guys
copied and pasted from the same article

nice to see we have SEARCH geniuses

Answer 5

when a star dies and it implodes following an explosion. then creating a rip in the space time continuum aka black hole.