Across
- 5. a galaxy with a bulge in the center and very distinctive spiral arms
- 7. the theory that states that the universe began with a tremendous explosion
- 13. a spinning neutron star that appears to pulsate as its beam of light passes the Earth
- 14. a diagonal pattern of stars on the H-R diagram
- 15. the death of a large star by an explosion
- 16. a star that expands and cools once it runs out of hydrogen fuel
- 17. a large cloud of dust and gas in interstellar space; the location of star formation
- 18. a group of older stars that looks like a ball of stars
- 19. a unit of length equal to the distance that light travels through space in one year
- 20. an object with more than three solar masses squeezed into a ball only 10 km across whose gravity is so strong that not even light can escape
- 22. how bright a light appears to an observer
- 23. a graph that shows the relationship between a star’s surface temperature and its absolute magnitude
- 24. a large grouping of stars in space
Down
- 1. the study of the origin and future of the universe
- 2. a star-like source of light that is extremely far away; one of the most powerful sources of energy in the universe
- 3. radiation left over from the big bang that fills all of space
- 4. the rainbow of colors produced when white light passes through a prism or spectrograph
- 6. the actual brightness of a star
- 8. a small, hot star near the end of its life; the leftover center of an old star
- 9. a spherical or elongated galaxy with a bright center and very little dust or gas
- 10. a group of stars that are usually located along the spiral disk of a galaxy
- 11. a galaxy that does not fit into any other category; one with an irregular shape
- 12. a star in which all the particles have become neutrons; collapsed remains of a supernova
- 21. an apparent shift in the position of an object when viewed from different locations