The Universe

3. The apparent movement of stars when observed at different times of the year.
9. The lens that magnifies an image. (3,5)
10. When a star runs out of energy and collapses, the rebounding material forms a massive explosion called.
11. Common issue of refracting telescopes, solved by using reflection.(9,10))
13. Evidence that galaxies are moving away from our own.
14. Another word for moon.
18. The lens at the end of a refracting telescope that collects and focuses light to form an image.
19. Process by which Hydrogen becomes Helium.

1. Rapidly spinning neutron star.
2. Another word for brightness.
4. The model of the solar system with the Earth at its center.
5. Commonly used to measure distances in space. (5,4)
6. The model of the solar system with the Sun at its center.
7. Type of star with an absolute magnitude +10 to +16 and temperature >4400 degrees celcius. (5,5)
8. A type of electromagentic wave that is emitted by our Sun.
12. Dense remnant of star that can only be seen as an absence of light.
15. A theory of how the universe started.
16. Force that pulls matter closer together.
17. A giant cloud of gas and dust in space where stars form.