Galaxy Notes
*Galaxy- a system of millions or billions of stars, together with gas and dust held together by gravitational attraction.
-Clusters: galaxies that travel together.
-3 main types:
-Spiral
-Elliptical
-Irregular
*Spiral
-Characterized by a bulge at the center and spiral arms
-Spiral shape is caused by the rotation of the galaxy
*Irregular
-Galaxies that do not fit into any other class
-As their name indicates, they ave irregular shapes.
*Elliptical
-Characterized by very bright centers and very little dust and gas
-Appear elongated or spherical and are basically massive blobs of stars
-Composed of mostly old stars
*Nebula- star "birth"
-Latin for "Cloud"
-Giant clouds of gas and dust
-Where new stars are formed
-Found in spiral galaxies
-Not found in elliptical galaxies
*Universe-
-All of space and the matter it contains
-Most of the universe is empty space
*The Big Bang Theory
-One theory of the formation of the universe
-It sttes that the universe began with a tremendous explosion
-Clusters: galaxies that travel together.
-3 main types:
-Spiral
-Elliptical
-Irregular
*Spiral
-Characterized by a bulge at the center and spiral arms
-Spiral shape is caused by the rotation of the galaxy
*Irregular
-Galaxies that do not fit into any other class
-As their name indicates, they ave irregular shapes.
*Elliptical
-Characterized by very bright centers and very little dust and gas
-Appear elongated or spherical and are basically massive blobs of stars
-Composed of mostly old stars
*Nebula- star "birth"
-Latin for "Cloud"
-Giant clouds of gas and dust
-Where new stars are formed
-Found in spiral galaxies
-Not found in elliptical galaxies
*Universe-
-All of space and the matter it contains
-Most of the universe is empty space
*The Big Bang Theory
-One theory of the formation of the universe
-It sttes that the universe began with a tremendous explosion