A "Nova" is a type of astronomical event that occurs when a white dwarf star in a binary system accumulates material from its companion star. This process leads to a sudden and dramatic increase in brightness, often making the star visible from Earth even if it was previously too faint to see. The explosion is caused by nuclear fusion igniting on the surface of the white dwarf. Novas are different from supernovae, which are more powerful explosions marking the death of a star. The term "nova" comes from the Latin word for "new," as these events can appear as new stars in the night sky. They are important for understanding stellar evolution and the chemical enrichment of the universe.