SAF cont.
- distance ~ 150,000 l.y.
- also distance to Large Magellanic Clouds (closest galaxy)
- Very important “step” on distance ladder
- Many Cepheid variables in LMC
- knowing distance, calibrate intrinsic brightness
- “inverse square law” for light (fig. 5-7).
- Now Cepheid’s are “standard candles”
- use them to measure distance to far-away galaxies
- calibrate the Hubble law of velocity vs distance
- measure the age of the universe!
- Strongest justification for Hubble Space Telescope