Is the nova the brightest star of all?

Answer 1

Depending on its distance from Earth, a nova may not outshine other bright stars in the sky.

A nova is the smaller of the stellar upheavals that can (temporarily) increase the brightness of a star. It occurs when gas accretes on the surface of a white dwarf.

A supernova is the general destruction of a star when its outer layers suffer gravitational collapse and then are blasted out into space. These cataclysmic events may make nearby supernovae the brightest objects in the sky, brighter even than the planets Venus and Mercury. But the brightness will fade rapidly over time.

Answer 2

A nova is actually a sudden, temporary increase in a star's brightness due to the explosion of material on its surface. These outbursts can make a star appear much brighter than usual for a short period of time, but they are not permanent changes in the star's intrinsic brightness.