Galaxies

2. interstellar gas clouds that emit visible light
5. this region of the galaxy contains mainly old stars and may contain large amounts of dark matter
8. this type of telescope is able to see the entire galaxy
9. age of the Milky Way
11. groups of stars that are gravitationally bound together
13. the correct shape of the Milky Way
14. The pale band of light spangled with stars stretching across the sky
15. There is a high density of these at the center of the disk
16. this region is a flattened collection of stars surrounding the core of the galaxy

1. the two stellar populations
3. the number of stars of each mass
4. the region of the sky where distant galaxies cannot be seen
6. This part of the galaxy has a dense swarm of stars and may contain a massive black hole
7. an interstellar cloud that completely obscures the stars behind it
10. distribution of stars, gas, and dust with a diameter of about 30 kpc
12. material that emits no radiation