Questions for Test #3

 

The material for the test will be found in the readings assigned in Crowe, chapters 3,through 6 (Paneck), the notes from the web site, and the in class quizzes.

 

  1. Who discovered the phenomenon known as the “aberration of light” and when was it discovered?  Explain with diagrams exactly what the aberration of light is.
  2. The aberration of light was the first direct evidence of what cosmologically significant phenomenon?
  3. Who is credited with discovering the proper motion of stars?  What is proper motion and in what units is it measured?
  4. List four major accomplishments for which William Herschel is remembered.
  5. What type of telescope did Herschel make popular and why was it more useful for his purposes than the refracting telescopes used by most astronomers of the time?
  6. What is the name of the first recognized woman astronomer since antiquity, in what period did she live, and in what astronomical work did she engage?
  7. Describe (and draw a rough sketch of) Herschel’s model of the galaxy that he developed near the end of the 18th century.  How did he arrive at this model?
  8.  What assumption did Herschel make to estimate the dimensions of the galaxy (i.e., the distance to the stars)?  What lead him to abandon this assumption later in his career?
  9. What two basic stellar properties indicate that a star might be close?
  10. What is the relationship between luminosity, apparent brightness and distance?  Suppose you are reading by a lamp that is five feet away from your book.  What happens to the amount of light falling on the book if the lamp is moved and placed 25 feet away?
  11. State the three laws of spectroscopy established by Wilhelm Bunsen and Gustav Kirchhoff.
  12. How did Plato and his school believe that light originated?
  13. What was Father Angelo Secchi’s original stellar classification scheme?
  14. List the seven major stellar spectral classes in the sequence we use today. Give the relationship between the spectral classes and temperature and the relationship between the spectral classes and color.
  15.  What were the earliest known lenses used by the Greeks?
  16.  Alhazen was a 10th century Persian who wrote extensively on optics and described a particular optical phenomenon later used in a common modern instrument.  What did Alhazen describe and what is it used for today?
  17.  In what era did Annie Jump Cannon live and for what is she remembered today?
  18.   Who was Roger Bacon, and for what two optical instruments is he known for today?
  19.  Explain the phenomenon known as the Doppler effect.
  20. What do we mean when we say that a star is blue shifted or red shifted?
  21.  What did William Herschel hope to find by observing double stars?
  22.  What was the definition of the word nebula as used by astronomers in the 19th century?
  23.  Using the wave model of light, “white light” consists of many different wavelengths.  How do our eyes distinguish between these wavelengths?  How do the longest wavelengths appear to us? How do the shortest wavelengths appear?
  24.  What two new techniques made up what was known as the “New Astronomy” in the middle of the 19th century?
  25.   Who invented the diffraction grating, what is it used for, and what does it seem to prove about the nature of light?
  26.  The planets Uranus and Neptune were discovered in very different ways.  Explain how each planet was discovered,
  27.   List two properties we know about all stars.  What third property can be derived from one of these?
  28.  What were the two major schools of thought about the nature of the nebulae in the 19th century?
  29.  What is the “zone of avoidance” and what did most astronomers at the end of the 19th century believe this indicated about the nature of spiral nebulae?
  30.   Who was Lord Rosse, and what significant discovery did he make?
  31.  Arrange the following stars (the first group whose parallax was measured) in order of luminosity relative to the sun (i.e., sort into more luminous, the same luminosity, and less luminous): Altair, Alpha Centuri, 62 Cygni, and Vega
  32.  Why was the nova that appeared in M31 (the Andromeda nebula) believed to discredit the “Island Universe” theory?
  33.  How did Ole Römer discover that light had a finite velocity and when did he announce the results?
  34.  Why was it necessary to observe Mars simultaneously in Paris and South America to determine its distance?
  35.  List everything you can think of which might make a star appear to be displaced from its plotted position on a star map.
  1.  Who was Henrietta Leavitt, in what era did she live, and for what is she remembered today? Explain how she arrived at her discovery and why it is important in determining the structure of the universe.
  2.  Answer the following questions on stellar parallax:
    1. Who is credited with first determining stellar parallax?
    2.  When did he do it?
    3.  What star did he measure?
    4. How far away is that star?
    5. What instrument did he use to determine the parallax? 
  3.  Give three arguments against the idea that some nebulae are external galaxies (“island universes”)
  4.  Give three arguments in favor of the idea that some nebulae are external galaxies (“island universes”)
  5. How did Harlow Shapley come to the conclusion that the sun is not in the center of the Milky Way?