Across
- 2. A series of stars to which most stars belong, represented on an HR Diagram as a continuous band extending from the upper left to the lower right.
- 4. A shift in frequency of a wave in relation to an observer who is moving relative to the source of the wave.
- 5. A system of millions or billions of stars, gas, and dust, held together by gravitational attraction.
- 7. A small, rocky body orbiting the sun
- 10. The brightness of a celestial object as it would be seen at a distance of 10 parsecs.
- 13. The brightness of a celestial object measured from Earth.
- 15. The displacement of spectral lines toward the red end of the spectrum in radiation from distant galaxies and celestial objects.
- 17. A graph in which the absolute magnitudes of stars are plotted against their spectral class.
Down
- 1. The range of wavelengths of frequencies over which electromagnetic radiation extends.
- 3. What happens when a star reaches the end of its life and explodes in a burst of light and energy.
- 6. The amount of light emitted by an object in a unit of time.
- 8. A way to explain how the universe began: A single point that expanded to the size of our universe today.
- 9. A celestial object consisting of a nucleus of ice and dust.
- 11. A shift in light wavelengths toward the blue end of the spectrum as an object moves toward us in space.
- 12. An area that contains all matter and space.
- 14. A cloud of gas and dust in outer space, visible in the night as an indistinct bright patch.
- 16. A massive, self-luminous celestial body of gas that shines by radiation derived from its internal energy sources.