Main-sequence star
Main-sequence star is a star that is in a stable phase of stellar evolution characterized by sustained hydrogen fusion in its core. This phase occupies a well-defined region of the Hertzsprung–Russell diagram.
Main-sequence stars are discussed in astrophysics, stellar evolution, and observational astronomy.
Status
Main-sequence stars are observed across a wide range of masses, temperatures, and luminosities. Models of their structure and lifespan are well developed, though details depend on composition and mass.