What is a supernova?

Question

Could someone please give me a simple answer that can be understood easily!

Thank you very much! ^_^

Answer 1

It happens at the end of a stars life (it is only possible for it to happen to a very big star, about 20-25 times bigger than our sun). Basically what happens is, the outer layer of the star just blows off. The inner part of the star had such a great amount of gravity, that it pulls in on itself. The size of the inner star decreases because its being pulled in to itself. Otherthings around it also get pulled in. This then causes a dent in the sky, or a black hole.

Answer 2

A supernova happens when a large star explodes.

Answer 3

It is an exploding star that picks up gases that can appear in the night sky under a good telescope for months.

Answer 4

Supernova is when a star of a certain size and above (our own sun is not massive enough to ever go supernova) runs out of fuel and the star explodes...now when I say explodes I mean KABLOOIE the force is so intense that the light from the nova is equal or greater than the SUM of ALL the light it gave off during it's entire life and the force is so intense it can fuse atoms into much heavier elements than iron (which is how astrophysicists think the heavy elements came into being).

A black hole is a dead star that has no fuel to burn so the pressure cannot balance out gravity and gravity condenses it into such a small, dense mass that it's gravity becomes so strong that not even light can escape.

A red supergiant is a dying star in which the fuel has been mostly used up and so the star cools and gets more red in color and expands due to it's decreased gravity not being able to hold the outer layers of the star in as close

Answer 5

ok well a supernova is when a young star that is about 40-100billions times bigger than our sun runs out of energy and claspses on it self (deu to gravity) and explodes most of the time the result is a black hole.

well a black hold is a body of mass that is so dense that it has an infinite amount of gravity so light cant even escape it.

a red super giant it basically a HUGE red giant.

Answer 6

When an aged star becomes more massive by consuming neighbour star, it eventually explodes and turns into a black hole.

Answer 7

Simple Answer:  A supernova is an exploding star.

More complex answer:  Only stars above a certain size will finish their life as a supernova.  Our sun will not.  The star needs to be about 9x the mass of our sun or more to explode.

Think of a star as a continuous explosion.  The fusion of hydrogen into helium (and eventually helium into heavier elements and so on) releases a *huge* amount of energy.  The star is kept from flying apart by its own gravitational attraction which is considerable.  Things settle down into the fiery globe we are familiar with with the effort to fly apart exactly canceled by the gravity pulling it together.

Eventually the star fuses all the fuel it has.  Once at iron it can no longer fuse heavier elements (fusing iron results in a net energy loss so fusion stops).  At this point there is now no force pushing "out" and gravity takes over causing the star to collapse rapidly.  This increases temperature and pressure inside the star dramatically and quickly causing iron and heavier elements to fuse and form.  This results in a catastrophic explosion which blows off most of the star into outer space.  When this happens the supernova releases so much energy it can outshine its entire galaxy!

Note when a star gets *really* big the resulting collapse will result in a black hole.  There is so much gravity that the star collapses completely in on itself and nothing escapes.  In between a supernova and a black hole you get a neutron star.  Gravity is not quite strong enough to collapse into a black hole and you get a Neutron Star.  Neutron Stars occur when all the electrons in orbit around atoms get crammed the nucleus of all the atoms.  Neutron Stars are about 10 miles in diameter and a teaspoon full of the stuff would weigh as much as Mt. Everest!

EDIT:  Black Holes - As I mentioned above when a star is really large (over 20x the mass of our sun) and collapses.  In this case the resulting supernova cannot blow off enough mass and there is enough gravity left over to continue a collapse.  Gravity is so strong the core of the star collapses to a point.  Its gravity is so strong that for an area around the singularity (called its "event horizon") absolutely nothing can escape, not even light.  Hence the name "black hole" since that is how it would appear if you could see one.

Red Supergiants - These are stars in the last phase of their life.  They will go supernova in the near (on stellar timescales) future.  As the star runs out of hydrogen in its core it starts fusing helium into nitrogen in the core and hydrogen into helium farther out from the core.  It keeps going up this scale till it is fusing hydrogen near the surface of the star and helium in a layer below and carbon below that like layers of an onion.  This causes the star to expand to a huge size (although its mass remains the same).  If such a star were in place of our sun the sun would engulf out to Mars and farther.  Once the core gets to iron and as nothing left we are on to the supernova stage.

Answer 8

"...What is a supernova?..."

There are several types of supernovas, but the most spectacular happens when a star that's at least 9 times more massive than our own sun simply can't support its own weight. It then collapses in on itself (implodes) and that results in a great explosion

"...Could you also describe a Black Hole and a Red Supergiant?!..."

Black holes are sometimes the end result of a supernova. If the original star that exploded is at least 10 times more massive than our sun, a black hole can be the end result. A black hole is simply an object with such immense gravity that not even light can pull away from it, hence the name 'black' hole.

Red supergiant stars are stars between 8 to 15 times more massive than the sun and are prime candidates for the supernova explosion.