Life Cycle of Stars

• A Nebula is a cloud of dust and gas

  
• Stars are formed from nebulae.

  
• Gravity pulls dust and gas together (nebula) creating a protostar.

  
• Temperatures rise as the protostar gets dense as particles collide. When temperature is high enough, Nuclear fuison forms helium nuclei.

  
• The Process of Nuclear fuison in the protostar, gives out a lot of energy, keeps the core hot. Creating a Star (Main Sequence Star)

  
• Once a star starts to run out of Hydrogen, It will not be able to go through Nuclear Fusion.

  
• Hydrogen runs out, The star Swells into a Red Giant (If small) or a Red Super Giant (if big). The surface cools down making it red. Heavier elements form in core.

  
• A small star forms a Red Giant.

  
• A big star forms a Red Super Giant.

  
• Small Star - Red Giant = becomes unstable - White dwarf = Solid, dense core = cools down - Black Dwarf

  
• Big Star - Red Super Giant = Glow brightly (more fuison) - Expand more - Explodes to Supernova - Neutron Star (if big) - Black Hole (if too big)

  
• Black hole - A massive star that is so dense that light is sucked in.