Across
- 2. The small spiral arm of the Milky Way where Earth and our Sun are located.
- 3. A mysterious force that is causing the expansion rate of the universe to accelerate.
- 7. An extremely large star that can fuse elements up to iron
- 8. An early stage in star formation before nuclear fusion begins
- 10. The nuclear process that combines lighter atoms into heavier ones inside a star
- 11. The distance light travels in one Earth year, equal to roughly 9.46 trillion kilometers.
- 16. The hot, dense core left behind after a low-mass star sheds its outer layers
- 18. A smooth, egg-shaped galaxy containing mostly old stars and very little gas or dust.
- 19. The law stating that the speed at which a galaxy recedes is directly proportional to its distance from us.
- 23. The classification system using the letters O B A F G K M
- 25. A giant cloud of gas and dust in space where new stars are born
- 26. An expanded, cooler stage when a sun-like star runs out of core hydrogen
- 27. The change in wave frequency caused by the relative motion between a wave source and an observer.
- 29. An object with gravity so intense that not even light can escape it
- 30. The scientific study of the origin, structure, evolution, and ultimate fate of the universe.
- 32. The stretching of light toward longer wavelengths as a cosmic object moves away from Earth.
- 33. The largest spiral galaxy in our Local Group, currently on a collision course with the Milky Way.
- 34. The violent explosion of a high-mass star at the end of its life
- 35. A category of galaxy with no symmetrical or defined shape, often rich in gas and dust.
- 36. An extremely dense stellar remnant left over from a supernova
Down
- 1. The barred spiral galaxy that contains Earth and our solar system.
- 4. Invisible matter that emits no light but exerts gravitational force, holding galaxies together.
- 5. The total amount of light output a star emits per second
- 6. The star property on the X axis of an HR diagram running high to low
- 9. The rainbow pattern of colors or dark emission/absorption lines used to analyze stellar composition and movement.
- 12. An expanding shell of gas blown off by an aging red giant
- 13. The dense, spherical center of a spiral galaxy packed tightly with older Population II stars.
- 14. The balance between the inward pull of gravity and outward pressure
- 15. An extremely bright and distant active galactic nucleus powered by a supermassive black hole.
- 17. The sparse, spherical outer region of a spiral galaxy containing old stars and globular clusters.
- 20. The shortening of light waves toward higher frequencies as an object moves toward the observer.
- 21. The element whose fusion in a massive star core triggers a supernova
- 22. The brightest star in our night sky with a white dwarf companion
- 24. A famous red supergiant star located in the constellation Orion
- 28. The small cluster of over 50 galaxies that includes the Milky Way and Andromeda.
- 31. The stable phase of a star's life where it fuses hydrogen into helium