The life cycle of a star depends primarily on its mass with bigger stars burning their fuel more quickly. For nuclear fusion in stars to begin, the elements must undergo extremely high temperatures and pressures. Elements heavier than hydrogen are scattered throughout the universe when a massive star explodes as a Supernova. All elements heavier than helium are produced in the core of a red supergiant. The blackbody spectrum emitted from a star changes as the star's temperature changes.