Here's why:

* Massive Increase in Brightness: Supernovae are known for their incredibly bright explosions, often increasing their luminosity by a factor of 10,000 or more.

* Temporary Event: Supernovae are not continuous events. They are a violent, short-lived explosion that marks the end of a star's life.

* Two Main Types: There are two main types of supernovae:

* Type Ia: These occur in binary star systems where a white dwarf star accretes matter from its companion until it reaches a critical mass and explodes.

* Type II: These occur when massive stars (8 times the mass of our Sun or more) exhaust their nuclear fuel and collapse under their own gravity.

Let me know if you have any other questions!