Across
- 1. A star that experiences rapid brightness variation
- 4. The type of galaxy with a flat, disk-like structure
- 5. A star in the last stage of its life
- 8. A small, cold star near the end of its life
- 10. The remnant of a massive star after a supernova
- 11. The theory that describes the universe’s beginning
- 12. The observable boundary of the universe
- 13. The initial phase of star formation
Down
- 1. A system of stars bound by gravity
- 2. Our galaxy
- 3. The law that describes the relation between a galaxy's velocity and its distance
- 6. . A dense stellar remnant formed by collapsed neutrons
- 7. The force that governs the motion of planets and stars
- 9. The energy that causes the expansion of the universe
- 13. A rotating compact star emitting radio waves