28. According to the models of the universe we discussed in this course, why do the galaxies move apart (why do we have Hubble’s law)?

10. Which law do astronomers use to determine the masses of the stars in a spectroscopic binary system?

35. Which of the following statements about Saturn’s rings is TRUE?

22. Measurements show a certain star has a very high luminosity (100,000 x the Sun’s) while its temperature is quite cool (3500o K). How can this be?

1. If you want to find stars that are just being born, where are the best places to search?

3. Which of the following statements about the main sequence stage in the life of a star is FALSE?

10. An astronomer wants to observe a cloud of cold neutral (not ionized) hydrogen, far away from any stars. What would be an instrument that could help in this task?

24. What do the surveys of the three-dimensional distribution of groups of galaxies reveal about how groups and clusters of galaxies are organized?

15. Objects orbiting around the center of the Milky Way obey Kepler’s 3rd Law. This means that:

23. The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn’s magnetism is: