Across
- 6. unseen mass that adds to the gravity of a galaxy, but can not be detected or seen
- 8. optical instrument that uses double convex lenses to collect light and a lens to magnify an image
- 10. DWARF giant star that has lost its outer layers, leaving behind a hot, dense core that continues to contact under gravity
- 12. cool darker areas of the sun's photosphere
- 13. study of how the universe began and what it is made of and how it continues to evolve
- 16. large group of stars, gas, and dust held together by gravity
- 17. late stage in a stars life cycle that occurs when its hydrogen fuel is depleted, its core contacts and its outer layers expand and cool
- 18. light-emitting surface of the sun
Down
- 1. energy that might be causing accelerated expansion of the universe
- 2. device that disperses light into its component wavelengths using a prism or diffraction grating
- 3. distance light travels in one year, about 9.5 billion kilometers
- 4. star pattern that appears to form images, used by astronomers to locate and name stars
- 5. the theory that the universe started with a big bang, or explosion and has been expanding ever since
- 7. section of a HR diagram that is plotted from the upper left to the lower right and contains 90% of all known stars
- 8. optical instrument that uses a concave mirror to collect light and a lens to magnify an image
- 9. telescope that collects and magnifies radio waves
- 11. our spiral shaped galaxy which contains the solar system and about 400 billion stars including the sun and measures about 100,000 light years across
- 14. the mass of the sun
- 15. cluster of 45 galaxies including the Milky Way