1. Vocabulary Chapter 27 - Stars Ne-bu-laNoun Nebula Large clouds of gas in space made up of hydrogen,... Stars and planets are formed out of nebulas.

2. Vocabulary Chapter 27 - Stars Pro-to-star Noun Protostar A cloud of gas undergoing gravitational contraction as it is developing into a star.

3. Vocabulary Chapter 27 - Stars Main Se-quence Star Noun Main Sequence Star Any star lying on a diagonal band that extends from hot-bright stars to cool-dim stars on the Hertzsprung-Russell diagram– our Sun.

4. Vocabulary Chapter 27 - Stars Nu-cle-ar Fu-sionNoun Nuclear Fusion Smashing nuclei of light elements, like hydrogen, together so they fuse, releasing lots of energy.

5. Vocabulary Chapter 27 - Stars Gi-antNoun Giant Third Stage Star when almost all of the hydrogen atoms have fused into helium. A large red giant star at least 10 times larger than the Sun. Our Sun will become a Red Giant in about 7 billion years.

6. Vocabulary Chapter 27 - Stars Red Su-per-gi-ant Red Supergiant A Third Stage star when almost all of the hydrogen has fused into helium. An extremely large red giant star at least 100 times larger than the Sun. The best known red supergiant is Betelgeuse, located in the constellation Orion, is 1,000 times larger than the Sun.

7. Vocabulary Chapter 27 - Stars Plan-e-ta-ry Ne-bu-laNoun Planetary Nebula Remains of stars that once looked a lot like our Sun. When sun-like stars die, they puff out their outer gaseous layers.

8. Vocabulary Chapter 27 - Stars White DwarfNoun A star, approximately the size of the Earth, that has undergone gravitational collapse and is in the final stage of evolution for low- mass stars. Beginning hot and white and ending cold and dark. Our Sun will die this way!

9. Vocabulary Chapter 27 - Stars No-vaNoun Nova A white dwarf that has an explosion is called a “Nova”.

10. Vocabulary Chapter 27 - Stars Su-per-no-vaNoun Supernova – Explosion of a Red Supergiant star. Possibly caused by gravitational collapse or implosion.

11. Vocabulary Chapter 27 - Stars Neu-tron Star Noun Neutron Star An extremely dense, compact star composed primarily of neutrons, from. the collapsed core of a supernova.

12. Vocabulary Chapter 27 - Stars Black HoleNoun A theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.

13. Vocabulary Chapter 27 - Stars High Utility Words

14. Vocabulary Chapter 27 - Stars El-e-mentsNoun Elements – Only the lightest elements, such as hydrogen and helium, were created during the Big Bang. The heavy elements that were essential to the formation of Earth and other rocky planets, including silicon, iron, nickel and zinc, were created much later, in exploding stars. Light Elements H = Hydrogen He = Helium Heavy Elements Au = Gold U = Uranium Si = Silicon Fe = Iron Ni = Nickel Zn = Zinc

15. Vocabulary Chapter 27 - Stars De-brisNoun Debris The remains of anything destroyed.

16. Vocabulary Chapter 27 - Stars Gra-vi-tyNoun Gravity The force exerted by all objects having mass on all other objects having mass.

17. Vocabulary Chapter 27 - Stars Ex-plo-sionVerb Explosion A violent expansion or bursting with noise. Im-plo-sionVerb Implosion – A bursting inward.