At this point, the outward pressure produced by the reactions can no longer balance the inward gravitational attraction between atoms. As a result, all the core can do is collapse under its own weight. As it does so, the star implodes, transforming gravitational energy into kinetic energy, or energy of motion. The core of the star collapses in on itself, but as it does so, it transfers to the star's atmosphere kinetic energy that sends the atmosphere exploding outward from the star's core. The particles of the star's atmosphere begin moving rapidly away from the star, tearing apart the star's atmosphere.
Astronomers know of several variations of supernovas, but they all fall into one of two main types.
The two kinds of supernovas are called Type I and Type II and are differentiated mostly by the presence of hydrogen in their debris. Type I supernovas tend to be older stars that have completely exhausted their hydrogen. Type II supernovas come from younger stars that have used up the hydrogen in their nucleus but have large amounts of hydrogen in their atmospheres. Astronomers can measure what elements exist in a star by examining its light because atoms of different elements emit and absorb electromagnetic radiation at different wavelengths. All supernova explosions produce clouds of debris and release huge amounts of energy, but Type I supernovas typically completely destroy their parent stars, while Type II explosions usually leave the stellar core behind.