Unit Four Study Guide
Astronomy - ASTR 122

The Milky Way Galaxy:

  1. Recall who first attempted to make a three dimentional map of our galaxy based upon the visible stars.
  2. Sketch the general shape of our Galaxy and where we are in relation to the galactic center.
  3. Know the physical dimentions (diameter, thickness, etc.) of our Galaxy.
  4. State what type of galaxy our Milky Way galaxy is.
  5. Know what our nearest galactic neighbor is.
  6. Describe the three regions of our Galaxy, the Halo, the Central Bulge, and the Disc, in terms of the type of stars found in each and their typical orbital trajectories.
  7. Explain what globular clusters are and where they are found.
  8. Be able to distinguish RR Lyrae and Cepheid Variable stars given a light curve.
  9. Know how the period of oscillation of RR Lyrae and Cepheid Variables are related to their luminosities.
  10. Describe what forms the visible spiral arms of our galaxy.
  11. State why it is that astronomers know that there is more mass to the galaxy that what is accountable by the visible material in the galaxy.
  12. Explain what types of objects or particles may account for the Dark Matter in the Universe.

Galactic Structure and Formation:

  1. Sketch out the 'tuning fork' diagram of galactic classification.
  2. Be able to distinguish between the four types of normal galaxies: elliptical, lenticular, spiral, and barred-spiral.
  3. Describe the current model of the formation of elliptical and spiral galaxies.
  4. For the four types of galaxies, recall what types of stellar populations are found.
  5. Know what distinguishes Population I and Population II stars.
  6. Explain why Type I Supernovae are important to the study of galaxies.
  7. Compare and contrast the three types of active galaxies: Seifert galaxies, radio lobe galaxies, and quasars.

Cosmology:

  1. Know what Edwin Hubble's main contribution to cosmology was.
  2. Recall Hubble's Law and how it relates to Einstein's theory of General Relativity.
  3. Be able to use a galaxy's redshift and Hubble's Law to calculate the distance to the galaxy
  4. Explain what the density parameter and what it implies about the future fate of our Universe.
  5. Differentiate between the three types of possible geometeries for the Universe: open, closed, and flat.
  6. Describe what the cosmic microwave background radiation (CMBR) is, why its important, and which spacecraft and terrestrial projects have investigated it.
  7. Know what is meant by the term 'vacuum genesis'.