Supernovas are enormous explosions that happen in space. They are like huge bombs blowing 

up, but in supernovas the bombs are stars. Gigantic stars or small dense stars in binary systems can create supernovas, but either way the explosions are very big. In fact, supernovas are one of the most explosive events known to our universe. Supernovas are what happen to stars towards or at the end of their lives. After stars become supernovas, their futures lie ahead of them as neutron stars, pulsars (or pulsating neutron stars), or black holes.

Types of Supernovas

There are two different types of supernovas: Type 1 and Type 2. The following are explanations of the two types:

Type 1 Supernovas

A Type 1 Supernova occurs where there are binary stars, or two stars that orbit closely with each other. The Type 1 Supernova occurs when one of the two stars is a dense, small star known as a white dwarf. When the two stars get too close to one another, the gravitational pull from the white dwarf pulls matter from the other star, and it becomes larger. When the white dwarf builds up enough matter from the other star, it collapses, ejecting matter outward and creating a Type 1 Supernova.

Type 2 Supernovas

A Type 2 Supernova occurs when the life of a star with great mass come to an end. As a massive star (more than 5 times the size of our sun) gets older, its core shrinks as its outer layers expand. It turns into one of two very large types of stars- a giant or a supergiant. The star continues expanding as it gets older. While the outer layers are expanding, the core creates energy and creates outward pressure. When the core becomes mainly iron and cannot create any more fusion (to create energy), it cannot create outward pressure to resist the gravitational pull of the star. The gravity of the star overpowers the outward pressure of the core, and the star collapses. The star’s outer layers rebound off of the star’s core and eject into space as an enormous cloud of gas and dust, creating a gigantic explosion, the Type 2 Supernova.

Nova or Supernova?

A nova occurs where there are binary stars, just like the Type 1 Supernova. Once again, the small and dense white dwarf pulls matter from the other larger star, but after it pulls the matter, it does not implode then explode like the Type 1 Supernova. If the matter that the white dwarf pulled from the other star is hot enough to create nuclear fusion (or fuse two atoms together and create energy) it does so. This fusion creates lots of energy that creates light and heat, so the star suddenly becomes very bright. This very bright star is called a nova. You may think that supernovas and novas are related because "supernova" is just "nova" with a "super" in the front of it, but really they are both very different. Supernovas got their name by mistake because they were once thought to be very bright novas. Therefore they were named "Supernovas" (or "Supernovae", which means the same thing).

The Remains of a Supernova

When supernovas occur, some of the star’s material becomes part of a nebula while what is left creates a neutron star or a pulsar. A pulsar is a neutron star that spins fast enough that it gives off pulses of radio waves. If that neutron star or pulsar is dense enough, it may become a black hole.

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