Dr. Pamela Gore Georgia Perimeter College Objectives Explain what constitutes a galaxy. Name some of the identified galaxies. Galaxies A galaxy is an organized system of hundreds of millions to thousands of billions of stars, sometimes mixed with interstellar gas and dust. Our sun and solar system are part of the Milky Way galaxy. Galaxies can be seen in every direction in space, each with billions of stars.
Galaxies often appear to be distinct but fuzzy patches of light.
Dreyer compiled the New General Catalog of nearly 8000 objects around 1900. Spiral galaxies are flat disks with a nuclear bulge, a halo of old stars, and spiral arms with young stars. Arms emerge fromt he ends of the bar. Dust is readily visible as dark streaks . The Milky Way galaxy is a spiral galaxy.