Across
- 4. cloud of interstellar gas and dust
- 5. when only two stars are gravitationally bound together and orbit a common center of mass
- 6. a stars power
- 9. how bright a star would appear if it were placed at a distance of 10 pc
- 11. a pulsating star
- 12. groups of stars (88 of them)
- 13. how bright a star appears
- 15. the splitting of heavy atomic nuclei into smaller, lighter nuclei, like uranium into lead
- 18. a unit larger than a light year used often by astronomers
- 19. collapsed, dense core of a star that forms quickly while its outer layers are falling inward, has a radius of about 10km, a mass 1.4 to 3 times that of the Sun, and contains mostly neutrons
- 21. massive explosion that occurs when the outer layers of a star are blown off
Down
- 1. in an H-R diagram, the broad, diagonal band that includes about 90 percent of all stars and runs from hot, luminous stars in the upper-left corner to cool, dim stars in the lower right corner
- 2. dark spots on the surface of the photosphere
- 3. outside the photosphere which is only visible only during a solar eclipse and when the photosphere is blocked
- 7. small extremely dense object,its gravity is so immense that nothing, not even light can escape it
- 8. is the combination of lightweight, atomic nuclei into heavier nuclei, such as hydrogen fusing into helium
- 10. is an arc of gas that is ejected from the chromosphere, or is gas that condenses in the inner corona and rains back to the surface
- 14. apparent shift in position caused by the motion of the observer
- 16. a hot, condensed object at the center of a disk shaped cloud of gas and dust
- 17. wind of charged particles (ions) that flows throughout the solar system and begin as gas flowing outward from the Sun's corona at high speeds
- 18. is the visible surface of the Sun
- 20. outermost layer of the Sun's atmosphere
- 21. violent eruptions of particles and radiation from the surface of the Sun