Test Topics ASTR 130 fall 2017

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Test #1, Chapters 5 & 6
This test allows you to have notes but no textbook, worksheets from class or homework papers. However you can make any notes about them that you wish and bring that resource to the test. You may print and bring any notes I have posted online and any notes of your own from class or the textbook.

This test will be a multiple choice document having 20 questions with room for written comments. Written comments will be taken into account in assigning credit. My tests are not multiple guess. You will be asked to apply concepts. So for example instead of being asked which kinds (colors) of light (em radiation) in a list has photons of the highest energy, you might be asked "Which of the following kinds of electromagnetic radiation would have photons that cause the most tissue damage in humans?" The correct answer would be the the em radiation with the shortest wavelength assuming the list had one or more of the following: gamma rays, x-rays, or ultraviolet light. The will always be a few content questions, 25 to 33%. Shame on you if you miss any of those because the answers should be in your notes. What is a content question? An example would be "Which kind of em radiation in the list below has the longest wavelength?" 

If you know the material, have good notes and know your notes, then you can perform well.

Chapter 5 You will be expected to:
  1. Identify the difference between energy and power.
  2. Identify the unit our class uses for measuring power.
  3. Identify what happens to white light that is reflected from colored paper or passes through a colored filter.
  4. Answer questions about the dual nature of light
    1. wave nature (wavelength, frequency, amplitude)
    2. particle nature (photons, photon energy
  5. Identify how the photon properties and the wave properties of light are related.
  6. Identify evidence for the wave nature of light and evidence for the particle behavior of light.
  7. Identify the velocity at which each type of light travels.
  8. Identify the in order the kinds of radiation in the em spectrum from short to long wavelength, from high to low frequency and from high to low photon energy.
  9. Identify an explanation of why your prof thinks it is wrong for astronomers to convert a radio signal from Saturn to sound and then say, "We are hearing the sounds of Saturn."
  10. Answer basic questions about the atomic model of matter:
    1. energy levels (electrons, electron energy, emission of light)
    2. nucleus (protons, neutrons, atomic number, isotopes)
    3. molecules
  11. Identify the property of matter we are measuring when we measure temperature.
  12. Answer questions about an ideal black body and the kinds of objects in astronomy that closely resemble an ideal black body.
  13. Answer questions about the phases of matter and phase changes in matter:
    1. solids (crystals)
    2. liquids
    3. gasses (vaporization)
    4. plasma (molecular dissociation, ionization, ions)
  14. Answer questions about the concept of pressure and how it impacts different phases of matter.
  15. Given an energy level diagram for an atom:
    1. Identify the transition with the largest energy and the least energy
    2. Identify the transitions that absorb energy and those that emit energy.
  16. Identify the conditions (type of physical object) producing the three different types of spectra we encounter in astronomy (continuous, emission [line], absorption [line])
  17. Identify the properties of object we learn from spectra and the method we use to find these properties:
    1. composition
    2. temperature (peak wavelength, color index [filters and B – V or similar–remember lab?], spectral lines present
    3. radial velocity (Doppler effect, redshift, blueshift), rotation rate.
Chapter 6
  1. Answer questions regarding the two important powers of a telescope.
    1. light gathering power
    2. resolving power (angular resolution)
  2. Identify the factors that limit the detail visible with a telescope and the cause of that limit:
    1. wavelength of light
    2. telescope diameter
  3. Identify what is meant by the diffraction limit.
  4. Calculate the light gathering power of a telescope compared to another telescope or the human eye.
  5. Identify why the magnifying power of a telescope is not important and is not a power of a given telescope.
  6. Calculate the magnifying power of a telescope from the focal length of the eyepiece and the telescope.
  7. Identify the reason why radio telescopes need to be very large to resolve (show detail) in objects easily resolved by our lab telescopes.
  8. Identify how the atmosphere affects ground-based astronomy and how those affects are reduced.
  9. Identify the advantages of interferometry and how it works.


Test #2, Chapters S2–S4, 15 (distance & brightness) and the magnitude handout

Chapters S2 –S4 (SR = special relativity, GR = general relativity, QM = quantum mechanics)
  1. Identify the two fundamental principles of SR.
  2. Identify the five major predictions of SR.
  3. Identify the astrophysical consequences of SR.
  4. Identify the fundamental idea behind GR.
  5. Identify the predictions of GR.
  6. Identify the astrophysical consequences of GR.
  7. Identify how gravitational waves are produced and the types of astronomical objects which produce them.
  8. Evaluate statements about gravitational lensing.
  9. Identify correct statements about wave-particle duality.
  10. Identify the two main ideas or principles on which quantum mechanics is based.
  11. Identify the astrophysical consequences of quantum mechanics.
Chapter 15 & and the handout (only Distance and Brightness)
  1. Determine the change in parallax angle that would result from changing the distance to a nearby star.
  2. Identify the difference between luminosity (L) and apparent brightness (b) and the difference between absolute magnitude (M) and apparent magnitude (m).
  3. Identify the information needed to determine the luminosity (L) or absolute magnitude (M) of a star.
  4. Identify how a star’s apparent magnitude (m) is related to its absolute magnitude (M).
  5. Determine the absolute magnitude (M) of a star given its distance and its apparent magnitude (m).
  6. Determine the apparent magnitude (m) of a star given its distance and its absolute magnitude (M).


Test #3, Chapters 15 &16

Chapter 15 Measuring Stars

  1. Rank stars according to surface temperature from a list of stars of different colors.
  2. Identify on an H-R diagram the regions corresponding to the main sequence, giants, supergiants, and white dwarfs.
  3. Rank stars on an H-R diagram according to size, temperature and luminosity.
  4. Estimate the relative masses of a main sequence stars from their locations on an H-R diagram.
  5. Determine the absolute magnitude of a star the spectral class with luminosity class and an HR diagram showing luminosity class.
  6. Apply the method of spectroscopic parallax to determine the distance when give the apparent magnitude, the spectral class with luminosity class and an HR diagram showing luminosity class.
  7. Calculate the distance to a Cepheid variable given its period of pulsation and its apparent magnitude.
  8. Identify the information needed to compute the mass of an orbiting system using Newton's version of Kepler's third law.
  9. Compute the sum of the masses in a simple binary star systems give the period and semi-major axis.
  10. Identify how the radius of a star can be computed from it temperature and its luminosity.
  11. Estimate the relative masses and lifetimes of main sequence stars from their locations on an H-R diagram.
  12. Distinguish between the two basic types of star clusters.
  13. Arrange star clusters in order of increasing age based on H-R diagrams of their stars.
  14. Identify the reason for two different populations of stars and the differences between Population I and Population II stars.
  15. Arrange star clusters in order of increasing age based on H-R diagrams of their stars.

Chapter 16 Star Formation

  1. Identify the gas and dust content of interstellar clouds forming stars.
  2. Identify an explanation of why stars form most easily in interstellar gas clouds that are both cold and dense.
  3. Identify an explanation of how molecular clouds cool to the low temperatures necessary to contract into a star.
  4. Identify an explanation of why the first stars could must have formed by a different mechanism that stars do today.
  5. Identify a description of how gravitational contraction eventually triggers nuclear fusion in a star-forming cloud.
  6. Identify a description of how conservation of angular momentum affects the formation of stars.
  7. Identify an explanation of why contracting gas clouds with masses less than 0.08 solar masses fail to achieve energy balance through steady nuclear fusion.
  8. Identify an explanation of why contracting gas clouds with masses greater than about a hundred solar masses fail to form stable lasting stars.
  9. Identify a description of how the time required for star formation depends on a star's mass.


Test #4

Chapter 17, The Lives of Stars
  1. Identify a star's characteristics predicted by its mass.
  2. Identify why a star as a whole expands when it exhausts its core hydrogen fuel and the core contracts.
  3. Identify what is happening inside and outside a solar type star and why it is happening when the star is
    1. a protstar
    2. at the ZAMS
    3. on the main sequence (MS)
    4. on the subgiant branch (SG)
    5. on the red giant branch (RGB)
    6. on the horizontal branch (HB)
    7. on the asymptotic branch and (AGB)
    8. formating of the planetary nebula (PN)
    9. a white dwarf (WD)
  4. Identify an explanation of why the helium fusion reaction requires a higher temperature than hydrogen fusion.
  5. Identify what kind of star in what stage of its life is know as a carbon star.
  6. Identify what happens to the core of a star after a planetary nebula forms.
  7. Identify in broad terms explain how the life of a high-mass star differs from that of our Sun.
  8. Identify why iron will not fuse in a normal star's core no matter how high the temperature.
  9. Identify what event initiates a high mass star supernova.
Chapter 18 Star Death
  1. Identify the three objects in the stellar graveyard, their sizes and ranges of masses and the stars that produce them.
  2. Identify the characteristics of a white dwarf and how its size depends on its mass.
  3. Identify a description of the model for making a nova.
  4. Identify a description of the model for making a white dwarf supernova.
  5. Identify a description of the model for a pulsar.
  6. Identify a description of the model for making an x-ray binary in a close binary system.
Chapter 19 Our Galaxy
  1. Identify the main components of our galaxy (disk, bulge, and halo) and for each component identify the specific objects found there, the kind of orbits followed by objects there and the characteristics of the stars found there.
  2. Identify the evidence for a supermassive black hole in the center of our galaxy.



The Final Exam covers the entire semester
Add the topics below to those above for a complete picture of the final exam

Chapter 19 Our Galaxy
  1. Identify how metallicity of star populations changes over time.
  2. Identify how can we use orbital properties (a variation on Kepler's 3rd Law) to learn about the mass of the galaxy.

Chapter 20, Other Galaxies
  1. Identify the primary differences between spiral, elliptical and irregular galaxies.
  2. Identify the Hubble law and its significance to cosmology.
  3. Relate the lookback time for a galaxy to its distance in light years. (Where are the oldest galaxies in the Universe?)


Chapter 21 Galaxy Evolution

  1. Identify accretion by a supermassive black hole as the energy source of a quasar and other active galaxies and active galactic nuclei (AGNs).
  2. Identify an explanation of why there are no quasars in the Universe near to us.


Chapters 22–23 The Formation of the Universe

  1. Define the terms dark matter and dark energy.
  2. Identify a description of the evidence for dark matter in galaxies.
  3. Identify a description of the evidence indicating that the expansion of the universe is accelerating.
  4. Identify a description of how the early universe produced the particles of matter of which make up everything we now observe.
  5. Identify a description of the origin of the cosmic microwave background.
  6. Identify the evidence in favor of the Big Bang theory.