The changes that take place in the characteristics of stars as they age.

(stellar=of a star) The different phases in the lifetime of a star, from its formation out of gas and dust, to the time after its nuclear fuel is exhausted. Based on observations of stars at various stages of their evolution, astronomers have developed a general theory of stellar evolution, by which the Sun is a typical "main sequance" star, in the middle of its evolutionary lifespan.

The processes by which stars condense out of primordial clouds, ignite nuclear burning processes, exhaust their nuclear fuel, and end their existence either in some kind of explosion or as a slowly dying cinder.

The changes experienced by stars as they originate, mature, and grow old.

The process of change that occurs during a star's lifetime from its birth to its death.

In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime; the hundreds of thousands, millions or billions of years during which it emits light and heat. Over the course of that time, the star will change radically.