Birth of a Black Hole

back | 1 of 7 | next

Red supergiant

A young, massive star creates energy by nuclear fusion, converting hydrogen into helium. That's what makes it shine. When all the hydrogen in the core is used up, the star begins fusing an outer shell of hydrogen that lies beyond what is now a helium core. At this later stage in its life, the star expands into a red supergiant (shown here).

Monster of the Milky Way homepage | NOVA homepage