LIFE CYCLE OF A STAR

1. Star formation:A Nebula

• A nebula is a cloud of gas and dust

Protostars

2. A protostar forms when the gases in a nebula condense due to an outside force such as an explosion acting upon it.

3. If the protostar’s center gets hot enough, nuclear fusion reactions will occur. When this fusion begins, a star is born.

Main Sequence Star

• 4. Main sequence stage: During nuclear fusion, Hydrogen continues to be changed into Helium.

Red Giant and Super giant Phase

5. Giants and Supergiants: When most of the hydrogen in the star’s core has fused to helium the star expands becoming a giant or supergiant.

6. Final Stage: White Dwarf:

• A star enters the final stage of its life when its nuclear fuel is used up.

• Less massive stars (like the sun), become white dwarfs, these are made entirely of a hot core.

7. Exploding Stars:

• A supernova is an exploding star of incredible brightness. A supernova explosion blasts much of the star’s matter into space.

8. Final Stage: Neutron Star:

• A neutron star is an extremely dense star made entirely of tightly packed neutrons.

• 9. A pulsar is a neutron star from which radiation is received in regular rapid pulses.

10. Final Stage: Black Hole:

• A black hole is a collapsed object from which no light or matter can escape.

• 11. The more massive a star is, the shorter its life will be.