Chapter 19: Stars, Galaxies, and the Universe

A galaxy is a collection of stars, dust, and gas held together by gravity. Types of Galaxies. Spiral Galaxies have a bulge at the center and spiral arms. The Milky Way Astronomers think that our solar system is in a spiral galaxy. Elliptical Galaxies About one-third of all galaxies are simply massive blobs of stars. These are called elliptical ... ................
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