What is the difference between a nova and a supernova remnant?

Nova and supernova are two astronomical events that involve the explosion of stars, but they differ in their characteristics and impact on surrounding space.

Nova

A nova is a sudden, short-lived brightening of a star caused by a thermonuclear explosion on its surface. This explosion occurs in a binary star system, where one star is a white dwarf and the other is a main sequence star. The white dwarf siphons off gas from the other star, and when the gas accumulates on its surface, it becomes hot and dense enough to undergo nuclear fusion reactions, triggering a sudden outburst of energy that causes the star to shine much brighter than usual.

Supernova Remnant

A supernova is a much more powerful explosion that occurs when a massive star exhausts its fuel and collapses under its own gravity, triggering a runaway nuclear reaction that blows the star apart. The explosion is so bright that it can outshine entire galaxies and can be seen from billions of light years away. After the explosion, the remains of the star form a supernova remnant, which is a glowing cloud of gas and dust expanding outward into space. These remnants are rich in heavy elements and are important in the formation of new stars and planets.

In summary, while both novae and supernovae involve explosions of stars, the difference between them lies in the intensity and duration of the explosion and the resulting impact on the surrounding space.