Use these questions to test your understanding. If you get them wrong, you will be linked back to the relevant part of the notes.
Be sure you study them thoroughly (don't just get a quick fix for your mistake) so your overall understanding is improved.
1. Why did astronomers in the 19th century believe that the solar system was close to the center of the Milky Way?
a. we are close to the center
b. they did not have photographic plates to detect very faint stars
c. their telescopes were too small to see the whole system
d. they needed infrared detectors
e. they did not realize how interstellar dust cut off their view
2. The Shapley-Curtis debate
a. was important philosophically because the topics touched on our place in the Universe
b. was decisively won by Shapley
c. was decisively won by Curtis
d. was an argument about the role of star formation in affecting our view of the cosmos
e. had to do with the superiority of Harvard College Observatory
3. That "spiral nebulae" were other galaxies like the Milky Way was first established when
a. we sent a spaceship to them
b. the new 100-inch telescope was used to resolve some of them into stars
c. from spectra that showed they had emission lines like the ones from the Milky Way
d. because they avoid the plane of the Milky Way
e. maps of the Milky Way in the HI line showed it to have spiral arms too
4. A "standard candle" for an astronomer is
a. a special candle of constant brightness maintained at the Bureau of Standards
b. an astronomical object whose luminosity can be determined independent of knowing its distance
c. a barred spiral galaxy
d. a votive candle of the usual size and wax content
e. a variable red supergiant star
5. Galaxy distances are important because
a. they let us calibrate parallax measurements
b. they help address the philosophical questions about our place in the Universe and how it is built
c. they show us which galaxies are coming toward us
d. they identify which galaxies are associated with each other in space
e. they tell us where to look to find stars with planetary systems
6. Henrietta Leavitt's period luminosity relation for RR Lyrae stars proved important because:
b. it was the first significant astronomical discovery by a woman
c. it explained why some star fields looked different in pictures taken at different times
e. it showed that they moved on the HR diagram
7. Galaxy distances are determined
a. just by using Cepheid variables
e. by a large variety of techniques that have to be used together, depending on the circumstances
8. Distance measurements to the galaxies around us show that
a. the Milky Way is isolated in space
b. the Milky Way belongs to a group of only three galaxies, including M31 and M33
c. the Milky Way is part of a galaxy group in which it and M31 are surrounded by many small galaxies
d. we are moving rapidly toward a certain point in space, leaving the nearby galaxies behind
9. The sun is located
a. in the outer part of the Milky Way's disk
b. in the halo of the Milky Way
c. near the center of the Milky Way
d. at an unknown location within the Milky Way
10. The biggest change in our view of our place in the Universe compared with the view 100 years ago is
a. then, we thought that the "Universe" was just the Milky Way
b. then, we believed the earth was at center of the solar system
c. then, we believed we were off at one edge of the Milky Way
e. then, we thought stars made their energy by chemical burning
11. What technical breakthough was revolutionizing astronomy 100 years ago?
b. the first mechanical calculators
c. photography began to be used in astronomy
d. accurate micrometers were introduced to measure double stars
e. radio astronomy became widely applied
12. The period-luminosity relationships for RR Lyrae and Cephid stars were easier to establish for stars in the Magellanic Clouds (nearby external galaxies) because
a. there are more of these stars in the Magellanic Clouds than in the Milky Way
b. they were easier to see in the Magellanic Clouds than in the Milky Way
c. the ones in the Magellanic Clouds are all at about the same distance
e. their proper motions are smaller, making comparisons over time with other stars more accurate
13. In the early 1900's it became possible to measure large numbers of RR Lyrae and Cepheid variables in the nearest galaxies because
a. telescopes were built larger than ever before
b. telescopes were put at high mountain sites for the first time
c. the first observatories were built in the southern hemisphere