ASTR 112 Study Guide

  1. Introduction
  2. Navigating the sky
  3. Light
  4. Atoms & Spectra
  5. Telescopes
  6. Sun
  7. Stars
  8. Low Mass Stellar Evolution
  9. High Mass Stellar Evolution
  10. Milky Way
  11. Galaxies

Introduction & Background Material

  • Define three units of length used in astronomy.
  • How do we use scientific notation?

Navigating the Sky

  • Define & differentiate between constellations and asterisms.
  • Describe 3 constellations in the winter/spring sky & describe how to locate them.

Light & Spectra

  • What are the main parts of an atom?
  • Explain the process of absorption and emission of light by atoms.
  • What are the three main types of spectra? List an example of a source for each.
  • How does a star’s spectrum tell us about its composition?
  • List the various kinds of radiation in the EM spectrum.
  • What types of radiation are able to reach Earth’s surface?


  • What is a telescope?
  • List the two main kinds of visible light telescopes. How are they different?
  • What are some benefits of mirror-based telescopes over lens-based ones?
  • How is magnification determined?
  • What is angular resolution? How does telescope size affect it?
  • What are some problems with visible light telescopes? ¬†Solutions?
  • What other wavelengths are also studied with telescopes?


  • List the three layers of the Sun’s atmosphere and a feature of each.
  • What are sunspots? How do they form?
  • Why is the corona so hot?
  • What is the solar cycle? What effect does it have on the Sun?
  • What is a CME? How does it differ from a prominence or flare?


  • What are the different kinds of stellar binaries?
  • What is the `center of mass’?
  • How can we determine the (surface) temperature of stars?
  • What is luminosity? What properties does it depend on?
  • What is an HR diagram? Sketch one and indicate major features.
  • What is the Main Sequence? Why is it important?
  • How do we determine the age of star clusters?
  • Explain the difference between apparent and absolute magnitudes.
  • Discuss the methods which make up the `distance ladder’.

Low Mass Stellar Evolution

  • Under what conditions do stars form?
  • What internal process defines a star?
  • What is hydrostatic equilibrium? Why is it important?
  • What is the Main Sequence? What period for a star does it represent?
  • Detail the stages of development (core & envelope) for a low mass star.
  • What is the composition of the core of a low mass star when it dies?
  • What are planetary nebulae? White dwarves? Brown dwarves?
  • What is electron degeneracy pressure? Why is it important?

High Mass Stellar Evolution

  • How is fusion in a high mass, main sequence star different than in a low mass star?
  • Detail the stages of development (core & envelope) for a high mass star.
  • Why can’t stars fuse iron?
  • What is a supernova?
  • How do we make use of supernova light curves?
  • Why can we be described as `star stuff’?
  • What is neutron degeneracy pressure? Why is it important?
  • When do neutron stars form? What are they?
  • What is a pulsar?
  • How do black holes form? What evidence do we have they exist?
  • What are supermassive black holes? Where can they be found?

Milky Way

  • What type of galaxy do we live in? What is its name?
  • Where in our galaxy is our Sun located?
  • How do we `weigh’ a galaxy?
  • What do galactic rotation curves imply about our galaxy?
  • What leads to the spiral structure in spiral galaxies?
  • What are the leading candidates for `dark matter’?


  • What were galaxies originally thought to be? ¬†Why?
  • List the three main types of galaxies.
  • What is a galaxy’s `halo’?
  • What overall structure do we see when we look at large numbers of galaxies?
  • Why do the two main kinds of galaxies have such different characteristics?
  • What sort of evidence is there for the importance of galactic collisions?
  • What are Quasars? Why are they only seen at great distances?