The Universe

2. Process by which Hydrogen becomes Helium.
8. A theory of how the universe started.
9. Common issue of refracting telescopes, solved by using reflection.(9,10))
11. The lens that magnifies an image. (3,5)
14. Type of star with an absolute magnitude +10 to +16 and temperature >4400 degrees celcius. (5,5)
15. The model of the solar system with the Earth at its center.
16. A type of electromagentic wave that is emitted by our Sun.
17. Evidence that galaxies are moving away from our own.
19. The apparent movement of stars when observed at different times of the year.

1. Dense remnant of star that can only be seen as an absence of light.
3. Another word for moon.
4. When a star runs out of energy and collapses, the rebounding material forms a massive explosion called.
5. The model of the solar system with the Sun at its center.
6. Force that pulls matter closer together.
7. The lens at the end of a refracting telescope that collects and focuses light to form an image.
10. A giant cloud of gas and dust in space where stars form.
12. Another word for brightness.
13. Commonly used to measure distances in space. (5,4)
18. Rapidly spinning neutron star.