Galaxy

4. pulsating stars that undergoes periodic changes in brightness due to expansion and contraction
8. observation that galaxies are moving away from us at speeds proportional to their distance from Earth
10. large spherical region that surrounds main structure of a galaxy. Includes disk and bulge
11. big system of gas stars dust and other celestial objects
13. collection of more than 50 galaxies gravitationally bound together
14. type of galaxy that has a smooth elongated and featureless appearance

1. type of spiral galaxy that has a central bar shaped structure
2. rate at which the universe is expanding
3. flattened rotating component of any spiral galaxy containing dust stars etc.
4. when light from distant galaxies/objects is stretched to long wavelengths
5. Galaxy without a defined shape or structure
6. Galaxy characterized by its distinct spiral arms that wind upward
7. densely packed spherical of oval shaped group of stars found in central region of galaxies
9. massive gravitationally bound system containing hundreds to thousands of galaxies
12. galaxies that emit much energy from a central region