Across
- 4. Formed when a low-mass star has exhausted all its central nuclear fuel and lost its outer layers as a planetary nebula
- 7. The distance light travels in a year
- 8. A supergiant star that explodes
- 10. Galaxies that look like smoke rings and are mostly made up of empty space
- 11. An example of a medium-sized star which has a lifespan of about 10 billion years
- 12. Lemaitre Belgian scientist who proposed the Big Bang Theory
- 13. These galaxies are oval-shaped, similar to a football or rugby ball. They do not have any arms.
Down
- 1. The fusing together of two nuclei to form one
- 2. Spiral arms radiate from a central bulge containing billions of stars. The bulge is circular in shape.
- 3. A large, bright star located over the North Pole
- 5. A celestial object of very small radius and very high density, composed predominantly of closely packed neutrons
- 6. A group of stars that can form an outline or pattern in space, typically interpreted as an animal, mythological person or creature, a god, or an inanimate object.
- 8. Very large, bright stars
- 9. Gases that collect in large swirling clouds mixed with dust
- 14. After glow from the Big Bang that spreads in all directions of the universe