The Life Cycle of a Star By Andy

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. View – 3. 10 minutes