Crossword 5

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Across
  1. 2. sequence star, Any stable star that is fusing hydrogen in its core
  2. 4. spectrum, A continuous spectrum crossed by dark lines. Form when light is passed though a cool gas.
  3. 6. class, a category for classifying a star, according to features of its spectrum, as a function of temperature and its absorption spectrum, that indicate the surface temperature of the star and the presence of particular atoms or molecules in its outer layers
  4. 10. star, a celestial object of very small radius (typically 18 miles/30 km) and very high density, composed predominantly of closely packed neutrons.
  5. 11. diagram, a chart that show the relationship between the absolute magnitude (luminosity) and the surface temperature of stars
  6. 13. the band of colors formed when light passes through a prism
  7. 16. class, A classification of stars according to their brightness (absolute magnitude), where Ia – Ib Supergiants, II, Bright giants, III,  Giants, IV, Subgiants, V,  Dwarfs (main-sequence stars)
  8. 17. hole, A collapsed star(s) that for a region of space having a gravitational field so intense that no matter or radiation can escape
  9. 20. an instrument that breaks up light into its characteristic colors
Down
  1. 1. dwarf, A white dwarf is the stellar core left behind after a dying star has exhausted its nuclear fuel and expelled its outer layers to form a planetary nebula.
  2. 2. cloud, a type of interstellar cloud, the density and size of which permit the formation of molecules (most commonly molecular hydrogen, H2), and the formation of H II regions.(Ionized hydrogen)
  3. 3. the actual brightness of a star. Depends only on the size and temperature of the star. (Magnitude)
  4. 4. magnitude, Amount of light a star actually gives off
  5. 5. magnitude, brightness of a star as it appears on the Earth
  6. 7. shift, a shift toward the red end of the spectrum of a star that is moving away from the earth
  7. 8. neutron star that gives off pulses of radio waves
  8. 9. a tremendous explosion in which a star breaks apart, releasing energy and newly formed elements
  9. 10. a star that suddenly increases in brightness in just a few hours or days
  10. 12. fusion, combining of two atomic nuclei to produce one larger nucleus, with the release of nuclear energy
  11. 14. spectrum, Series Emitted light of lines of different frequencies (colors) from matter Every element emission spectrum is unique.
  12. 15. (of a star), A stellar core is the extremely hot, dense region at the center of a star. For an ordinary main sequence star, the core region is the volume where the temperature and pressure conditions allow for energy production through thermonuclear fusion of hydrogen into helium.
  13. 18. effect (for light), apparent change in the wave-length of light that occurs when an object is moving toward or away from the Earth
  14. 19. a huge cloud of dust and gas between the stars