Stars

How bright a star appears from Earth.

A region of space where gravity is so strong that nothing, not even light, can escape.

The boundary around a black hole beyond which escape is impossible.

A large, luminous star that has exhausted much of its core hydrogen.

The element produced during hydrogen fusion in most stars.

A graph that compares the luminosity and surface temperature of stars.

The process in which hydrogen nuclei combine to form helium inside stars.

The balance between the inward pull of gravity and the outward pressure produced by fusion.

The total amount of energy a star emits each second.

The diagonal band where most stars spend the majority of their lifetimes fusing hydrogen into helium.