Stellar evolution

In astronomy, stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from hundreds of thousands to billions of years.Stellar evolution is not studied by observing the life of a single star—most stellar changes occur too slowly to be detected, even over many centuries. Instead,  astrophysicists come to understand how stars evolve by observing numerous stars, each at a different point in its life, and simulating stellar structure with computer models.
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