Across
- 1. The brightness of a celestial object
- 5. A small very dense star that is typically the size of a planet.
- 6. A cloud of gas and dust in outer space
- 9. A change in the identity or characteristics of an atomic nucleus that results when it is bombarded with an energetic particle
- 10. A graph that plots the luminosity or temperature of stars
- 11. A super large star that is even bigger than a giant
- 12. Short for nuclear fusion
Down
- 2. The Galaxy we are located in
- 3. A Star of great size and luminosity compared to the ordinary stars of the main sequence
- 4. A system of millions or billions of stars
- 7. A theoretical stellar remnant; cooled to the point where it no longer emits visible light
- 8. All existing matter and space considered as a whole