Across
- 6. The distance that light travels in a one year.
- 10. The brightness that a star would have at a distance of 32.6 light-years from Earth.
- 12. The brightness of a star as seen from the Earth.
- 14. A celestial body that orbits the Sun, is round because of its own gravity, and has cleared the neighborhood around its orbital path.
- 16. One of the highly dense planets nearest to the Sun; Mercury, Venus, Earth, and Mars.
- 17. A collection of stars, dust, and gas bound together by gravity.
- 18. One of 88 regions into which the sky has been divided in order to describe the locations of celestial objects; a group of stars organized in a recognizable pattern.
- 19. The time required for a body to complete a single orbit.
- 24. An observed change in the frequency of a wave when the source or observer is moving.
- 26. The sun and all of the planets and other bodies that travel around it.
- 28. A large could of gas and dust in interstellar space; a region in space where stars are born.
- 29. A planet that has a deep massive atmosphere, such as Jupiter, Saturn, Uranus, or Neptune.
- 30. Quasi-stellar radio source; a very luminous object that produces energy at a high rate.
Down
- 1. An object so massive and dense that even light cannot escape its gravity.
- 2. The theory that all matter and energy in the universe was compressed into and extremely small volume that 13 to 15 billion years ago exploded and began expanding in all directions.
- 3. The location on the H-R diagram where most stars lie; it has a diagonal pattern from the lower right to the upper left.
- 4. A star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons.
- 5. A star that suddenly becomes brighter.
- 7. A very large and bright star whose hot core has used most of its hydrogen.
- 8. Radiation uniformly detected from every direction in space; considered a remnant of the Big Bang.
- 9. The degree of elongation of elliptical orbit (symbol, e)
- 11. A small body from which a planet originated in the early stages of development of the solar system.
- 13. A region of the solar system that starts just beyond the orbit of Neptune and that contains dwarf planets and other small bodies made mostly of ice.
- 15. A large celestial body that is composed of gas and that emits light.
- 20. The tendency of an object to resist being moved or, if the object is moving, to resist a change in speed or direction until an outside force acts on the object.
- 21. A rotating cloud of gas and dust from which the Sun and planets formed; also any nebula from which stars and exoplanets may form.
- 22. A small, hot, dim star that is the leftover center of an old star.
- 23. The study of the origin, properties, processes, and evolution of the universe.
- 25. An apparent shift in the position of an object when viewed from different locations.
- 27. A rapidly spinning neutron star that emits pulses of radio and optical energy.