Across
- 2. a stars _____ indicates it's temperature
- 5. groups of stars that have regularly recognized positions
- 7. a cloud of gas and dust
- 10. the intrinsic brightness, independent of how bright it appears
Down
- 1. the hot center of a nebula becomes a _________
- 3. ________ is fused to helium by thermonuclear fusion in the Sun's core
- 4. the nearest star to earth
- 6. the closest planet to the sun
- 8. the third planet from the sun
- 9. _____ planets are composed of high-density solid rock