1. Suppose you suspected a certain object in the sky to be a quasar. What sort of observations would you perform to confirm your hypothesis? 2. Explain why astronomers do not use any of the standard...

1. Suppose you suspected a certain object in the sky to be a quasar. What sort of observations would you perform to confirm your hypothesis?

2. Explain why astronomers do not use any of the standard candles described in Chapter 16 to determine the distances to quasars.

3. Explain how the rate of variability of a source of light can be used to place an upper limit on the size of the source.