1. { To Infinity and Beyond… The Classification of Stars and Galaxies

2. Set-Up Page 74: Nebula Medium Stars Massive Stars Spiral Galaxies Elliptical Galaxies Irregular Galaxies Glue only down the spine of the paper!

3. Nebula Nebula are the birthplace of all stars. They are extremely large. Each nebula can create up to 100,000 stars. 1.Dark Nebula- no near stars 2. Emission Nebula- near hot stars 3. Reflection Nebula- near cool stars.

4. Medium Stars Mass determined by amount of matter in nebula. Gravity pulls matter together and spins. Proto star heats up. Nuclear fusion occurs and the star begins to shine. Our Sun is a medium-sized star!

5. Massive Stars Mass determined by amount of matter in nebula. (Has a lot of matter!) Gravity pulls matter together and spins. Proto star heats up. Nuclear fusion occurs and the star begins to shine.

6. Spiral Galaxies Also called “disk- shaped” because of the way it is viewed from the side. Arms spiral out of center. Made of gas and dust collected by gravity. Young and old stars present. Halo is present.

7. Elliptical Galaxies Large 3D ellipse that is round or oval in shape. Has a bulge, but no disk. Contains cool gases and dust held together by gravity. Mainly old stars present. Halo is present.

8. Irregular Galaxies Contains all the galaxies that do not fit into the other two categories. Rich in gas and dust. May show signs of a disk or bulge. Young and old stars present. Halo is present.