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Stars: Crash Course Astronomy #26

Key Ideas

As this video progresses, key ideas will be introduced to invoke discussion.

Key Ideas

Think about the following questions as you watch the video


  1. 00:39 What are two different reasons that stars appear to differ in brightness?
  2. 01:12 What is a spectrum?
  3. 01:32 What does it mean that a star gives off a continuous spectrum?
  4. 01:50 What does a star’s atmosphere do to its continuous wavelength?
  5. 02:25 What did Max Planck determine about bluer versus redder stars?
  6. 03:12 How does today’s star classification system arrange stars?
  7. 03:44 What letter classification is our Sun?
  8. 04:33 Why are there no green stars?
  9. 05:37 What is luminosity?
  10. 05:57 What two things does a star’s luminosity depend upon?
  11. 07:10 Describe the three groups of stars Hertzsprung and Russell saw when they plotted a chart of stars’ luminosity versus its temperature.