Across
- 3. the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance.
- 4. a tightly packed group of stars within a larger star formation
- 7. star having a regular cycle of brightness with a frequency related to its luminosity
- 10. he ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer.
- 12. a galaxy that emits up to thousands of times more energy than a normal galaxy.
- 15. a huge collection of gas, dust, and billions of stars and their solar systems, held together by gravity.
Down
- 1. a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy
- 2. structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity
- 5. a nearly spherical volume of thinly scattered stars, globular clusters of stars, and tenuous gas observed surrounding spiral galaxies
- 6. are twisted collections of stars and gas that often have beautiful shapes.
- 8. a smooth ellipsoidal or spherical appearance, and they have far less structure than spiral galaxies do
- 9. a phenomenon where the wavelength of light is lengthened as it travels through expanding space.
- 11. galaxy with a black whole in the center
- 13. a disk component of the Milky Way that contains stars, gas, and dust in circular coplanar motion around the galactic center.
- 14. a galaxy group that includes the Milky Way.