Fall 2000 ASTR 1120-001 Quiz 5

Choose the single best answer and enter it on your scantron form. Be sure to fill in your name and student number.

1. What observational development led to the realization that the Milky Way is made up of myriads of stars?
   (a) Hipparcos counted stars in it; (b) Galileo Galilei looked at it with a telescope; (c) The Earl of Rosse discovered spiral structure in it; (d) Harlow Shapley studied globular clusters in it; (e) Henrietta Leavitt found Cepheids in it.

2. Harlow Shapley deduced that the center of our Galaxy lies toward Sagittarius from the observation that:
   (a) globular clusters are concentrated in that direction; (b) x-ray binaries are concentrated in that direction; (c) J. C. Kapteyn's survey showed more stars in that direction; (d) there is a black hole in that direction; (e) galaxies are more redshifted in that direction.

3. A Hubble diagram is a diagram of:
   (a) luminosity versus temperature; (b) mass versus radius; (c) period versus luminosity; (d) recession velocity versus distance; (e) the space telescope.

4. Which of the following statements about Cepheid variables is false?
   (a) They are yellow supergiant stars; (b) their large luminosity (for a star) means that they can be seen far away; (c) the luminosity of a Cepheid can be inferred from its period; (d) Cepheids vary because they are in binary systems; (e) Cepheids provide the best way to measure distances to nearby galaxies.

5. The fact that galaxies are redshifted tells us that:
   (a) they appear red; (b) they are receding from us; (c) they are rotating; (d) they are star clusters; (e) they contain black holes.

6. How far out do you have to look before you see the Hubble expansion of the Universe?
   (a) Beyond the Solar System; (b) beyond the Orion spiral arm; (c) beyond the Milky Way; (d) beyond the Local Group; (e) beyond the Local Supercluster.

7. From the observed value of the Hubble constant we can deduce: (a) that Dark Matter exists; (b) the distance to the center of the Milky Way; (c) how fast the Milky Way is rotating; (d) the age of the Solar System; (e) the age of the Universe.

8. Which of the following statements about the Local Group is false?
   (a) The Local Group is the group of about 30 galaxies to which the Milky Way belongs; (b) The Local Group is the local region of the Universe which has turned around from the general expansion and is starting to collapse; (c) The two largest galaxies in the Local Group are the Andromeda galaxy (M31) and the Milky Way; (d) The Local Group is about 1 Mpc in radius; (e) Most of the galaxies in the Local Group are giant Elliptical galaxies.

9. What can we tell from the rotation curve of a galaxy?
   (a) How much mass there is in the galaxy; (b) how much gas there is in the galaxy; (c) how many stars there are in the galaxy; (d) what the mass is made of; (e) how much star formation is going on in the galaxy.

10. Which of the following is not a common consequence of a collision or near collision between galaxies?
    (a) Individual stars collide; (b) bursts of star formation; (c) Spiral galaxies may lose their disks and become Ellipticals; (d) tidal tails; (e) spiral density waves may be excited.