Which star is brighter; a giant or a dwarf?

Question

Why?

Answer 1

A giant, of course. Which has more destructive power, a hand grenade or a hydrogen bomb?

Answer 2

At first glance, sounds like a simple question.
But think a little deeper, and you will find situations where the dwarf is brighter (even though the first impulse is the giant is brighter).

And of course "brighter" is a subjective term - the assumption is that you mean "appears brighter in visible light".
An object could be very dim in visible light, yet extremely bright in infrared, ultraviolet, or x-rays.

If the dwarf is a newly-created white dwarf, it would be intrinsically brighter. The total energy output of the dwarf and the giant might be the same, but the giant has more surface area to radiant the energy, so the white dwarf's brightness would be "concentrated" into a smaller area.

If the dwarf is only 5 light years away and the giant is 100 light years away, then the dwarf would appear brighter to our eyes.

If the giant is a red giant, then a white dwarf would naturally appear brighter (white light is brighter than red light).

If you happened to be inside the outer envelope of an expanding red giant, it would not appear as a star but as a glow all around, so any star outside the star's atmosphere would appear brighter.

If the dwarf was a newly-created white dwarf with a massive magnetic field (magnetar), the light emitted may be red-shifted due to the interaction with the magnetic and gravitational field. Or the energy could be given off more in x-rays and gamma rays than in visible light, so the star as a whole could appear dimmer.

There are probably other situations where the answer is 'that depends on..."

Answer 3

A giant, because its surface area is much larger.

A dwarf has only a small area emitting light, so is quite dim.

Answer 4

Giants. Dwarfs burn at a slower rate.

Answer 5

a red giant