Across
- 3. Clouds of ionised gas that emit their own light at optical wavelengths
- 4. metal-poor, with metallicities ranging from approximately 1/1000th to 1/10th that of the Sun
- 7. A massive, spherically-shaped and densely-packed group of stars that is gravitationally bound and stable over billions of years
- 8. A flattened system of matter that is circular coplanar motion about a common center
- 9. A model that explains the spiral structure of galaxies
- 11. Most metal-rich, with metallicites ranging from approximately 1/10th to three times that of the Sun
- 12. A distinctive structural component found in certain types of galaxies
- 13. interstellar clouds that contain a very high concentration of dust
Down
- 1. when light from a star is scattered or reflected off a neighboring dust cloud
- 2. more loosely bound groups that typically contain anywhere from tens to thousands of stars
- 4. composed entirely of primordial gas - hydrogen, helium and very small amounts of lithum and beryllium
- 5. A spherical cloud of stars surrounding a galaxy
- 6. a region of sky that appears devoid of extragalctic objects at optical wavelengths
- 10. The galaxy in which the Solar System resides