Download Chapter 24 Vocabulary

Chapter 24 Vocabulary
1. constellation- grouping of stars that has a shape resembling an animal,
mythological character, or other object and is thus named for it
2. magnitude- in earthquake studies, a measure of the energy released by an
earthquake; the Richter scale is used to describe earthquake magnitude
3. parallax- the apparent shift in position of an object when viewed from two
different points, such as your left eye and right eye
4. light-year- unit used to measure distance in space; the distance that light travels in
one year (about 10 trillion km)
5. main sequence- on a Hertzsprung-Russell diagram, the diagonal band that
includes 90% of all stars
6. H-R diagram- graph that shows the relationship of a stars temperature to its
absolute magnitude
7. nebula- large cloud of gas and dust in space that may be the beginning of a star
8. giant- late stage in a star’s life-cycle where the core has contracted and grow
hotter, causing its outer layers to expand
9. white dwarf- late stage in a stars life-cycle where its core runs out of fuel and its
unstable outer layers escape into space, leaving the white-hot core
10. supergiant- late stage in the cycle of a very large star, when the core reaches high
temperatures, heavy elements formed by fusion, and the star’s outer layers expand
11. Doppler shift- change in wavelength that occurs in any kind of wave energy
(light, radio, sound) as the source of energy moves toward you (the wavelength
shortens) or away from you (the wavelength lengthens)
12. neutron star- final stage in the life cycle of some stars, where the core collapses
and becomes so dense that only neutrons can exist there
13. black hole- final stage in the life cycle of some stars,; the remnant of a star is so
dense that not even light can escape its gravity field
14. photosphere- the innermost of the 3 layers of the sun’s atmosphere, radiates the
light we see
15. chromosphere- the intermediate layer of the 3 layer of the sun’s atmosphere, lying
between the photosphere and the corona
16. corona- the outermost and largest of the 3 layers of the sun’s atmosphere,
extending from the chromosphere outward millions of kilometers into space
17. sunspots- dork spots on the sun’s surface that show up because they are cooler
than surrounding areas
18. binary systems- system of two stars orbiting one another
19. galaxy- massive grouping of gas, dust, and stars in pace; held together by gravity
20. big bang theory- the leading theory of the origin of the universe
21. extraterrestrial life- life that may exist in the universe outside earth-