Across
- 1. the first stage in the life cycle of a star
- 3. measures the amount of light reaching Earth
- 4. a huge cloud of dust and gas from which stars form
- 7. the total amount of light given off by a star
- 8. a stable star in the main category in the H-R diagram
- 11. the explosion of a very large star
- 12. an enormous hot ball of gas held together by gravity which produces energy through nuclear fusion reactions in its core
- 13. a large star with low temperature and high brightness
- 14. very large, bright star that may be blue or red, depending on its temperature
Down
- 1. the expanding outer shell of a sunlike star. This matter is blown away as the core shrinks to become a white dwarf
- 2. theory that the universe began as a huge explosion 10 billion to 20 billion years ago
- 3. a system of two stars orbiting each other that are gravitationally tied together
- 5. a small star with a high temperature and low brightness
- 6. reactions which combine light elements such as hydrogen into heavier elements such as helium, releasing energy
- 8. the spiral galaxy to which our solar system belongs
- 9. a method of studying an object by examining the visible light and other electromagnetic waves it creates
- 10. the distance light travels through space in one year
- 15. a group of stars, dust, gas, and other objects held together by gravitational forces