Life Cycle of a Star

NEBULA A huge cloud of gas and dust within a galaxy where new stars are born. A nebula can be several light-years across

PROTOSTAR A star in the process of forming Gas and dust gather together because of gravity Protostars are getting hotter and more dense

MAIN SEQUENCE STAR Longest stage in a star’s life Most stars are in the main sequence stage Hydrogen fusing into helium Stars stay in the M.S. for about 10 billion years Our star is almost 5 billion years old

Expanding Hydrogen runs out Core collapses and heats up Expands hundreds of times its diameter In about 5 billion years the Sun will expand past Earth’s orbit, consuming and burning the Earth

MASSIVE STAR Red Super Giant AVERAGE STAR Red giant Like our sun Like our sun

Massive Average SUPERNOVA Core collapses and violently explodes Shines very brightly Explosion can last for days NOVA Smaller explosion Becomes 1000’s of times brighter Then returns to original brightness

Massive Average NEUTRON STAR Very dense Sends out radio waves PULSAR is a spinning neutron star Pulsar transmits radio waves like a lighthouse emits light WHITE DWARF Continues to burn Dimshrinks

Massive Average BLACK HOLE So much mass that it continues to collapse Gravity so high that light cannot escape BLACK DWARF When a white dwarf runs out of fuel Cold, dark and very small