Astronomy 10 Spring 2000

Worksheet #5

1. In what sort of situations would an astronomer prefer to use the 2.4m Hubble Space Telescope instead of the 10m Keck telescope? When would she prefer the reverse? Think of several types of astronomical observations (or objects) for each.

2. Suppose an atom had 5 equally space energy levels. What would its spectrum look like?

3. Suppose you have a sodium street lamp, and you look through a sodium flame at the street lamp. What sort of spectrum do you expect to see? What will happen if you remove the flame? (Do you have enough information to fully answer this? What else might you like to know?)

3. Given the angular resolution of 1 arc sec afforded by "regular" telescopes, for how distant a star can we measure its parallax? How do you think we know the distances for a large sample of stars? How large a sample do you think it is? What can we do to improve the situation?

4. The spectrum of a star can contain a lot of information. Think of 4 things you can learn from it about the star? Be specific about how you would extract the information from the spectrum (what you would measure, how would it tell you the information?).