Unit Four Study Guide
Astronomy - ASTR 122
The Milky Way Galaxy:
- Recall who first attempted to make a three dimentional map of our galaxy
based upon the visible stars.
- Sketch the general shape of our Galaxy and where we are in relation to
the galactic center.
- Know the physical dimentions (diameter, thickness, etc.) of our Galaxy.
- State what type of galaxy our Milky Way galaxy is.
- Know what our nearest galactic neighbor is.
- 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.
- Explain what globular clusters are and where they are found.
- Be able to distinguish RR Lyrae and Cepheid Variable stars given a light curve.
- Know how the period of oscillation of RR Lyrae and Cepheid Variables are
related to their luminosities.
- Describe what forms the visible spiral arms of our galaxy.
- 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.
- Explain what types of objects or particles may account for the Dark Matter in the Universe.
Galactic Structure and Formation:
- Sketch out the 'tuning fork' diagram of galactic classification.
- Be able to distinguish between the four types of normal galaxies: elliptical,
lenticular, spiral, and barred-spiral.
- Describe the current model of the formation of elliptical and spiral galaxies.
- For the four types of galaxies, recall what types of stellar populations are found.
- Know what distinguishes Population I and Population II stars.
- Explain why Type I Supernovae are important to the study of galaxies.
- Compare and contrast the three types of active galaxies: Seifert galaxies,
radio lobe galaxies, and quasars.
Cosmology:
- Know what Edwin Hubble's main contribution to cosmology was.
- Recall Hubble's Law and how it relates to Einstein's theory of General Relativity.
- Be able to use a galaxy's redshift and Hubble's Law to calculate the distance to the galaxy
- Explain what the density parameter and what it implies about the future fate of our Universe.
- Differentiate between the three types of possible geometeries for the Universe: open, closed, and flat.
- Describe what the cosmic microwave background radiation (CMBR) is, why
its important, and which spacecraft and terrestrial projects have investigated it.
- Know what is meant by the term 'vacuum genesis'.