Life Cycle of a Star

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

The following are REAL photographs of nebulas taken with the Hubble Space Telescope. Cool, huh!

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

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

Expanding Massive Star: Average Star: “Red Super Giant”“Red Giant” Expanding Massive Star: Average Star: “Red Super Giant”“Red Giant” Hydrogen runs out Hydrogen runs out Core collapses and heats up Core collapses and heats up Expands hundreds of times its diameter Expands hundreds of times its diameter In about 5 billion years the Sun will expand past Earth’s orbit, consuming and burning the Earth In about 5 billion years the Sun will expand past Earth’s orbit, consuming and burning the Earth

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

Supernova

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

Neutron Star

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

Black Dwarf Star This is concept art of a black dwarf against a background field of stars.

Cluster or group of stars close together in space. Each galaxy may contain billions or trillions of stars.

There are 4 types of Galaxies 1. Spiral 2. Elliptical 3. Barred Spiral 4. Irregular

Spiral

Elliptical

Barred Spiral

Irregular