Edwin Hubble and Milton Humason discovered that there was a linear relationship between a galaxy's ...

Edwin Hubble and Milton Humason discovered that there was a linear relationship between a galaxy's ____.
 
  a. rotation curve and distance
 b. mass and luminosity
 c. age and distance
 d. apparent recession velocity and distance
  e. mass and recession velocity

Question 2

Which type of focus is most common for larger telescopes?
 
  a. Cassegrain focus
 b. Galilean focus
 c. Newtonian focus
 d. Copernican focus
 e. Schmidt-Cassegrain focus

Question 3

Cepheids and globular clusters are limited in their ability to measure the distance to galaxies because they ____.
 
  a. are too rare
 b. are not bright enough to detect at large distances
 c. behave differently in other galaxies than they do in our own
  d. do not appear in dwarf galaxies
 e. are only found in elliptical galaxies

Question 4

What telescope instrument is used to counter the eastward rotation of Earth?
 
  a. Newtonian focus
  b. sidereal drive
 c. active optics
 d. Cassegrain focus
  e. floppy mirrors

Question 5

An astronomer would find a type Ia supernova in a distant galaxy useful as a(n) ____.
 
  a. spiral tracer
 b. gravitational lens
  c. age calibration
 d. rotation curve
 e. standard candle

Question 6

What is a major selecting factor for astronomers looking to place a telescope atop a mountain?
 
  a. non-turbulent airflow
 b. percentage of tree-coverage
 c. amount of precipitation
 d. the country it is located within
  e. the economics of the location