What are the differences between a supernova and a nova?

A supernova is a massive explosion that occurs when a star runs out of fuel, while a nova is a smaller explosion caused by a white dwarf star.

Supernovae are the most powerful explosions in the universe, releasing huge amounts of energy and creating heavy elements. They occur when a star runs out of fuel and its core collapses, causing a massive explosion. There are two types of supernovae: Type I, which occur in binary star systems when a white dwarf star accumulates too much mass from its companion star, and Type II, which occur in massive stars when they run out of fuel.

Novae, on the other hand, are smaller explosions caused by a white dwarf star in a binary system. When the white dwarf accretes material from its companion star, it can become hot enough to ignite a nuclear reaction on its surface, causing a sudden increase in brightness. Unlike supernovae, novae do not destroy the star and can occur multiple times.

In terms of brightness, supernovae are much brighter than novae, with some supernovae being visible from Earth even during the day. Novae, on the other hand, are typically only visible with telescopes or binoculars.

Overall, while both supernovae and novae are explosive events in the universe, they differ in their causes, effects, and overall magnitude.