9- Evolution of high-mass stars

Learning goals

  • List the sequence of stages for evolving high-mass stars.
  • Identify how the H-R diagrams of clusters enable astronomers to measure the ages of stars and test theories of stellar evolution.
  • Describe how the death of a high-mass star differs from that of a low-mass star.
  • Explain the origin of chemical elements up to and heavier than iron.
  • Estimate the main-sequence lifetime of a star from its mass.
  • Explain why low-mass stars grow larger and more luminous as they run out of fuel.
  • Sketch post-main-sequence evolutionary tracks on the H-R diagram.
  • List the stages of evolution for low-mass stars.
  • Describe how planetary nebulae and white dwarfs form.
  • Explain how some close binary systems evolve differently than single stars.

Outline

  1. High-mass stars follow their own path.
    • The CNO cycle
    • The high-mass star leaves the main sequence line.
  2. Star clusters are snapshots of stellar evolution
    • Cluster Types
    • Cluster ages.
    • Main-sequence turnoff.
  3. High-mass stars go out with a bang.
    • Binding energy.
    • The final days in the life of a massive star.
    • The collapse of the core and subsequent explosion.
  4. The spectacle and legacy of supernovae.
    • The energetic and chemical legacy of supernovoe.
    • Neutron stars and pulsars.
    • Case Study: M1 (Crab Nebula)
    • Case Study: SN 1987a

Activities:

Extra Stuff