So the ball is gradually increasing helium, hydrogen-burning also follow the outward expansion of the outer material and heat expansion of stars up to the red star or red supergiant transformation.

• 如此氦球逐渐增大，氢燃烧层也跟着向外扩展，使星体外层物质受热膨胀起来向红巨星或红超巨星转化。