12.1 & Science Edvin.c Block:C

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Across
  1. 2. is the angle between an object's rotational axis and its orbital axis.
  2. 3. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night.
  3. 5. a specific area of the celestial sphere as defined by the International Astronomical Union.
  4. 7. are stars that have burned up all of the hydrogen they once used as nuclear fuel.
  5. 9. lifetimes that range between 50 million and 20 billion.
  6. 12. a scatter graph of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their spectral classifications or effective temperatures.
  7. 13. a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the Sun.
  8. 14. the shift in frequency (Doppler shift) of acoustic or electromagnetic radiation emitted by a source moving relative to an observer as perceived by the observer: the shift is to higher frequencies when the source approaches and to lower frequencies when it recedes.
  9. 16. spend billions of years fusing hydrogen to helium in their cores via the proton-proton chain.
  10. 17. the state of being fused.
  11. 18. a type of stellar remnant that can result from the gravitational collapse of a massive star after a supernova.
Down
  1. 1. go through a similar process to low mass stars in the beginning, except that it all happens much faster.
  2. 4. Are by far the most common type of star in the Milky Way, at least in the neighborhood of the Sun, but because of their low luminosity.
  3. 6. an interstellar cloud of dust, hydrogen, helium and other ionized gases.
  4. 8. is a large mass that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium.
  5. 9. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays.
  6. 10. an interstellar cope a telescope that uses infrared light to detect celestial bodies. Infrared light is one of several types of radiation present in the electromagnetic spectrum.
  7. 11. Astronomy. a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.
  8. 15. mathematician and astronomer