‘Supernova’ is a singular term, and ‘supernovae’ is a plural of supernova. Supernova is the last stage of the life of a star.

The interstellar nursery of cloud of dust and gas is called as Nebula. Planetary nebulae is a type of nebula. They are created when a main sequence star grows into a red giant and casts off its outer layers.

Nebula is a cloud in deep space consisting of gas or dirt/dust (e.g. cloud formed after a star explodes). A group of numerous stars, dust, planets and other interstellar matter, tied together by a...

Nebula is a cloud in deep space consisting of gas or dirt/dust (e.g. cloud formed after a star explodes). Supernova is the last stage of the life of a star and is a very huge explosion from a dead star.

The sudden brightening of the star is known as nova, whereas, more brightening in the star that signals the start of the end is known as supernova.