unit 7

3. How fast light travels (i.e., 300,000 km/s); the maximum speed at which all matter and information in the universe can travel
8. A galaxy with a long oval shape, a bright center,no apparent internal structure or spiral arms, and very little dust or gas
11. Rotation center of a galaxy
12. A celestial body consisting of a mass of gas held together by its own gravity in which the energy is generated by nuclear reactions in its interior
13. All of space and the matter space contains
14. Category of stable stars in the middle developmental phases that plot along a continuous diagonal belt on the Hertzsprung-Russell diagram
16. A galaxy with a bulge in the center and very distinct long arms winding around the center
17. A galaxy with very little symmetry that does not fit into any category

1. Streaming arcs of millions of stars swirling around the center of a spiral-shaped galaxy
2. The galaxy in which Earth and the Sun are located
4. The death of a large star by explosion
5. Bands of dust that appear as dark ribbons against the bright stars in a galaxy
6. Large cloud of gas and dust in interstellar space; the location of star formation
7. The remains of a star or other large object that collapsed under its own gravity to form a superdense object with gravity so strong that light cannot escape its pull
9. The intensity, or brightness, of light from a celestial body, which can be used to identify the body’s characteristics
10. A plot of the surface temperature (color) of stars vs. their luminosity (brightness)
15. A large grouping of stars in space