Cypress College ASTR 116 Homework
Astronomy 116, Homework CHAPTER 14 (A) The Milky Way Galaxy. Due:
Print Last, First Name and date on the small Scantron in INK. Print
your last name in BIG BLOCK letters on the back of the Scantron.
Use a No. 2 pencil to fill out Scantron. Read the chapter.
Look at the videos and simulations in the CD-ROM. Answer all True/False and
Fill in the Blank questions. Then answer the following questions and
turn in your Scantron only. Choose the best answer.
1. What perception of the Milky Way Galaxy did astronomers have at the
beginning of the twentieth century?
- a) They believed that the Earth rested inside concentric spheres,
with the Milky Way stars fixed to the outermost sphere.
- b) They believed that the Milky Way was one of billions of galaxies
in the universe.
- c) They believed that the Milky Way was the entire universe.
- d) They believed that, because the Sun was at the center of the
Milky Way, it was impossible to see the rest of the universe.
2. For what type of object is the period-luminosity relation used for
determining distances?
- a) RR Lyrae variables.
- b) Cepheids.
- c) Eclipsing binaries.
- d) 21 centimeter radiation.
3. What observation of the Galaxy suggests it is much larger than the
halo and contains a large amount of matter not in the form of stars?
- a) The rotation curve.
- b) Motions of the globular clusters.
- c) The shape of the spiral arms.
- d) Infrared observations of the center of the Galaxy.
4. What type of variable star is used to determine the distances to globular
clusters?
- a) RR Lyrae stars
- b) Cepheids
- c) T Tauri
- d) flare stars
- e) novae
5. Which of the following is not found in the Galaxy's halo?
- a) globular clusters
- b) old stars
- c) stars with random, three dimensional orbits
- d) red stars
- e) emission nebulae
6. The object located at the center of the Galaxy is believed to be a ________.
- a) a large supergiant
- b) an enormous emission nebula
- c) a black hole
- d) a massive supernova
- e) a massive star formation region
7. All RR Lyrae stars have about the same
- a) distance
- b) apparent magnitude
- c) luminosity
- d) galactic rotation speed
8. With respect to age, the stars in the Galactic disk are
- a) young
- b) old
- c) both young and old
9. The time it takes the Sun to travel around the center of the Galaxy
is about
- a) 25,000 yrs
- b) quarter million years
- c) quarter billion years
- d) 2 billion years
10. The Sun's galactic motion is in a ______ orbit.
- a) nearly circular
- b) highly eccentric
- c) very erratic
- d) retrograde
11. In time, the shape of the spiral arms of the Milky Way will
- a. wind up tighter
- b. become more open
- c. tend to remain the same as they are now
12. The Milky Way has about ____ stars.
- a. 100 thousand
- b. 100 million
- c. 100 billion
- d. 100 trillion
- e. 100 quadrillion