Star Life Cycle

• What is the first stage of stars life cycle called?


  -The first stage is the nebula.
• What is the nebula?

  -The nebula is a cloud of dust and gas called the nebula mostly composed of hydrogen
• What happens to the nebula?

  -Gravity pulls together the gases and this causes the mass to fall together. This causes the nebulas gas to heat up and glow forming the next stage
• What is the next stage called?


  -It is a protostar
• What happens during the protostars life cycle?

  -particles of gas and dust collisions causes an increase in their kinetic energy leading to temperature increase. This Eventually resulting in a specific temperature that allows for hydrogen nuclei to fuse and make helium. This process releases energy keeping the core hot. This forms the next stage
• What is the next stage of a stars life?

  -The main sequence star
• What happens during the main sequence star stage?


  -the main sequence star is the longest and most stable stage in a stars life cycle

  -Our sun has been in main sequence for over 4 billion years and is estimated to be for another 6.5 billion years

  
• What happens in the next stage of the stars life cycle?

  -The next stage of a stars life depends upon the stars mass and size

  A smaller star will form a red giant

  A larger star will form a red super giant star
• What happens to create the red giant (Smaller star) phase?

  -The hydrogen fuelling the star begins to run out. Most of hydrogen nuclei from core has been fused into helium

  -Nuclear fusion slows

  -The star shrinks and then swells and cools forming the red giant

  -Fusion continues in the shell around the core
• What happens to form the next stage known as planetary nebula?


  -The outer layers of the star is released and the core burning helium releases massive amounts of energy. This forms a planetary nebula. The core then collapses forming the next stage
• What is the next stage in a small stars life and what happens?

  -The core collapses into itself leaving a smaller very hot dense core known as the white dwarf