1. What perception of the Milky Way Galaxy did astronomers have at the beginning of last century?
2. What is the Sun's location within the Milky Way?
3. Measuring which two quantities of our galaxy allow for a determination (calculation) of the Milky Way's mass?
4. Matter belonging to the Galaxy can be traced out to _______ [what distance] from the center.
5. The object located at the center of the Galaxy is calculated and predicted to be a ________.
6. All RR Lyrae stars have about the same ___ .
7. With respect to age, the stars in the Galactic disk are ____ .
8. Our solar system lives in the Milky Way's ____ . [name which part]
9. The rotation curve for our galaxy (speed vs distance from center) is _________, compared to the "Keplerian curve", at large distance from the center.
10. Most of the mass of the Milky Way is predicted to exist in the form of ___ .
11. The interstellar ______ absorbs light from stars and makes them appear fainter than they otherwise would appear.
12. The fuzzy band across the sky which we call the Milky Way is actually the light from millions of stars in the ______ component of the Galaxy.
13. Neutral hydrogen gas, bright young O and B stars, Cepheid variable stars, and emission nebulae all map out the position of the ______, in the Milky Way.
14.The Sun is currently estimated to be about ______ from the center of the Galaxy.
15. Variable stars are stars whose ______ varies with time.
16. Elliptical galaxies tend to contain _____ stars and lack _____.
17. A spiral galaxy whose central region is a bright, bar-like source of light is called a(n) ______ galaxy.
18. Giant elliptical galaxies may be the result of ______.
19.Going from galaxy type Sa, to Sb, to Sc, there is a decline in the size of the galaxy's _______.
20. When galaxies collide, the individual stars, generally, do not collide. (True/False)
21. The Hubble Ultra Deep field is data from galaxies that are _____ .
22. Galaxies evolve by ____ .
23. In terms of luminosity, quasars are ____ .
24. Star formation in the earliest galaxies of the universe was ____