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On the Shoulders of Giants

Organization of the universe

THE UNIVERSE: 3 theories1. Open, expands forever2. Closed, like a saddle3. expanding and

contracting

Galaxies: contain stars, huge clouds of gas and dust (nebulae) which revolve around a nucleus.Three types

Spiral galaxies: Very organized like our Milky Way galaxy

Elliptical Galaxies: Sphere or flattened disk, older stars, little gas and dust

Irregular galaxies: No specific shape

Stars: Made up of mostly Hydrogen and Helium. Formed by collapsing gas and dust

Nebulae: Birthplace of stars, globs of gas and dust. Full of radio, UV, IR, and X-Rays

Star Clusters: Open (Pleiades) and Globular(Hercules)

Single star: Our sun. Single star systems are relatively uncommon.

Binary Star systems: Double Stars. Very common type of star system.

Novas: nuclear explosion of a white dwarf star. Causes increased brightness of a star.