Supernovas

　　Supernovas are a class of violently exploding stars that become super bright after eruption. There are two main classes, Type I and Type II. This depends on how they detonate. Supernova explosions release tremendous amounts of radio radiation, x-radiation and cosmic rays, as well as other elements. In some cases, the collapsing of a star produces a black hole. The gravitational field is so strong that not even light can escape.

　　Historically, only seven supernovas were known to have been recorded before the 17th century. The most famous occurred in A.D. 1054. The remnants today are seen as Crab Nebula. This supernova was recorded by Chinese and Korean observers.