Procyon B is a white dwarf star, which is the remnant of a star that has exhausted its nuclear fuel. White dwarfs are very dense and small, and they emit very little light.

Procyon B is about 10,000 times dimmer than the Sun. This means that it emits only 1/10,000th of the light that the Sun does.

Here's a more detailed breakdown:

* Absolute magnitude: Procyon B has an absolute magnitude of +10.7, while the Sun has an absolute magnitude of +4.83. This means that Procyon B is about 5 magnitudes fainter than the Sun.

* Luminosity: Each magnitude difference corresponds to a factor of 2.512 in luminosity. Since Procyon B is 5 magnitudes fainter, it is (2.512)^5 ≈ 10,000 times less luminous than the Sun.

It's important to note that these are just approximate figures. The exact luminosity of Procyon B can vary slightly depending on the specific model used to calculate it.