Across
- 1. A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.
- 4. The brightness of a star measured from earth.
- 8. A cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
- 9. The brightness of a star measured at ten parsecs
- 10. A graph in which the absolute magnitudes (intrinsic brightness) of stars are plotted against their spectral types (temperatures).
- 11. The intrinsic brightness of a celestial object (as distinct from its apparent brightness diminished by distance).
- 17. An increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other.
Down
- 2. A series of star types to which most stars belong, represented on a Hertzsprung–Russell diagram as a continuous band extending from the upper left (hot, bright stars) to the lower right (cool, dim stars).
- 3. That all the distances in the universe are stretching out at the same rate.
- 5. The displacement of the spectrum to shorter wavelengths in the light coming from distant celestial objects moving toward the observer.
- 6. The displacement of spectral lines toward longer wavelengths (the red end of the spectrum) in radiation from distant galaxies and celestial objects.
- 7. A small rocky body orbiting the sun.
- 12. All existing matter and space considered as a whole; the cosmos.
- 13. A star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.
- 14. A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
- 15. A celestial object consisting of a nucleus of ice and dust and, when near the sun, a “tail” of gas and dust particles pointing away from the sun.
- 16. A fixed luminous point in the night sky which is a large, remote incandescent body like the sun.