Life Cycle of A Star

• How is the protostar formed?

  Beginning stage of how a star is formed :

  1. Starts as a huge cloud of dust and gas particles in space
  2. The force of gravity pulls the particles closer together
  3. The compressed mass of particles form a protostar
• What is a protostar?

  • Hot dense mass produced by increasing gravity
• A main sequence star in a distant galaxy is the same size and mass as the Sun.

  Explain why the star is stable while it is in the main sequence stage of its life cycle.

  1. Gravitational force inwards and forces as a result of fusion reactions outwards.
  2. Are in equilibrium / balanced
• Main sequence star : How does a star form a red giant?

  • Expand to become a red giant
• Main sequence star : How does a star become a white dwarf?

  • Collapse to become a white dwarf
• Main sequence star : How does a star become a black dwarf?

  • Cool to become a black dwarf
• What stars are about the same size as the sun?

  • Red giant
  • White dwarf
  • Black dwarf
• What is a supernova?

  • The explosion of a massive star
  • Much bigger than the sun