main sequence ršte-ye farist Fr.: séquence principale An evolutionary stage in the life of a star when it generates its energy by the conversion of hydrogen to helium via → nuclear fusion in its core. Stars spend 90% of their life on the main sequence. On the → Hertzsprung-Russell diagram it appears as a track running from top left (high temperature, high luminosity, high mass) to lower right (low temperature, low luminosity, low mass). See also → zero age main sequence (ZAMS), → terminal age main sequence (TAMS). |