Center for Magnetic Self Organization
in Laboratory and Astrophysical Plasmas
Adapted from NASA Night Sky Network
The Life Cycle of Stars Over time, the hydrogen in a gas cloud is pulled together by gravity and begins to spin around a growing protostar. In this process (called accretion), the gas is heated to more than 10 million °C , nuclear fusion occurs, and the star begins to glow brightly for millions to billions of years.
When the hydrogen fuel supply in the core of the star begins to run out, the core becomes unstable and collapses. The outer layers expand, cool, and glow red, forming a red giant.
In low mass Sun-like stars, the outer layers of the red giant are expelled and a planetary nebula is formed. The leftover core becomes a white dwarf and eventually cools to a black dwarf.
In a massive star (>10 solar masses) the red giant will explode in a supernova. If the remaining core is 1.4 to 3 solar masses, a neutron star will form, while a more massive core remnant will collapse under its own gravity, forming a black hole.