Across
- 2. a collection of stars, dust and gas bound together by gravity
- 4. one of the most common elements in a star
- 6. nuclear fusion takes place in a star's ______
- 7. space and all matter and energy in it
- 10. is the brightness of stars if they were all moved to the same distance from Earth (10 parsecs)
- 12. coldest stars are this color
- 13. a relatively large spherical body that orbits a star
- 15. there are ____ planets in our solar system
- 16. actual brightness of an object such as a star
- 17. our galaxy is not an elliptical or irregular galaxy it is a ____ galaxy
- 18. one of the most common elements in a star
- 19. this planet is special because it has the perfect atmosphere and water which makes it habitable
Down
- 1. the sun and all of the planets and other bodies that travel around it
- 3. average distance between Earth and the Sun
- 5. hottest stars are this color
- 8. a large celestial body that is composed of gas and that emits light
- 9. if you know a star's temperature, then you know a star's _____
- 11. is the brightness of a star as seen from Earth (not absolute magnitude)
- 14. name of the galaxy we live in