Nebular Hypothesis and The Star Cycle

2. A large cloud of dust and gas in space
4. Creation of energy by joining the nuclei of two lighter weight atoms to create one heavier atom (2 hydrogen atoms forming a single helium atom). This is the way stars produce energy.
5. A large, old luminous star; has a relatively low surface temperature and a diameter large relative to the sun. Fusing helium in it's core to carbon.
6. hole The final stage in the life cycle of a very massive star, where the core's mass collapses to a point that its gravity is so strong that not even light can escape.
8. A developing planetary body that grows by the accumulation of planetesimals
11. A contracting cloud of gas and dust; the earliest stage of a star's life
12. The idea that our solar system was formed from an enormous rotating cloud of dust and gases approximately 4.5 billion years ago
13. A star and all the planets and other objects that revolve around it
14. A star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons. These stars are extremely dense and only about 12 miles across.
15. An extremely bright star of very large diameter and low density.

1. A normal star that is undergoing nuclear fusion. Our sun is an example of this.
3. Small celestial bodies that will collide to become protoplanets
7. A flat, rotating disk of gas and dust surrounding a young star. This is where planets form.
9. A former red giant star that has used up its helium and its outer layers escape into space, leaving behind a hot, dense core.
10. A massive explosion that occurs at the end of supergiant star's cyle; the star releases large amounts of energy in all directions.