The Life Cycle of a Star By Andy Kimmelshue

The birth of a star Stars are formed from gas and dust pulled together by gravity inside of a Nebula. A Nebula is a star nursery. Inside the Nebula, the gas and dust begin to spin and heat which creates a protostar.

Nebula

Main Sequence Stars As the temperature of the protostar increases, nuclear fusion begins, producing massive amounts of energy. At this point, these stars reach equilibrium and stay this way for the majority of their lives. Our sun is an example of a Main Sequence Star.

Red Giants/Supergiants Once the hydrogen is used up in the core, the core will contract, and the outer layers will expand, cool, and glow red. This increases the stars size dramatically, and depending on it’s size, it can follow two paths…………

1.) White Dwarf Once the helium in the core has all be converted into carbon, the core collapses, the outer layers are expelled into planetary nebula. The White Dwarf will eventually cool completely, and become a Black Dwarf and creating no light.

2.) Supernova Nuclear fusion continues creating heavier elements at the core, and causing the core to collapse in on itself. This force between the gravity and the atoms will cause a supernova.

Neutron Star If the star was 1.5 to 3 times the size of our Sun, any remaining mass will collapse into a small, dense neutron star. It collapses so much that protons and electrons combine to form neutrons. A Neutron Star has a solid surface.

Black Hole For stars larger than that, its remaining mass will collapse into a black hole; a deep gravitational warp in space. A Black Hole has an event horizon not a solid surface. ViewView – 3.10 minutes