The sun

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The sun
2012-04-28 16:12:28
Astro1 exam2

the sun
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  1. Granulation on the surface of the Sun is caused by
    convective currents carrying heat from beneath the surface
  2. What is a spicule on the Sun?
    a jet of rising gas in the chromosphere
  3. Suppose that, at night, the brightness of a light bulb is measured from a certaindistance and then the light bulb is moved to a distance twice as far away. Howbright will the light appear compared to the earlier measurement?
    1/4 as bright
  4. What is the dominant mechanism by which energy is transported through theinterior of the Sun?
    by photons (radiative transport of energy)
  5. Hydrogen "burning" by fusion reactions occurs only in the deep interior of theSun (and other stars), because this is the only place in the Sun where
    the requisite conditions of high temperature and high density occur.
  6. The Sun has existed for a very long time without change in its size, appearance,or behavior. This means that it must be in hydrostatic equilibrium. Under theseconditions, which two parameters must be in exact balance within the Sun?
    inward force of gravity and outward gas pressure
  7. Why should you NEVER look directly at the Sun?
    Looking directly at the Sun causes blindness.
  8. The total time that the Sun will spend converting hydrogen to helium in its core is
    about 10 billion years
  9. What process provides the power for the Sun?
    fusion of hydrogen into helium
  10. What is the structure of a typical large sunspot?
    a dark center surrounded by a less dark area
  11. If you were to look at one kilogram of material taken from the surface of theSun and 1 kilogram taken from the center, which of the following statements would betrue of these two 1 kilogram masses?
    The kilogram from the surface would contain more hydrogen than the one from the center.
  12. Helium fuses at a higher temperature than hydrogen because
    there is more repulsion between two helium nuclei
  13. Place the three atmospheric layers of the Sun in order of increasingtemperature.
    chromosphere, photosphere, corona
  14. How much matter is converted to energy in the Sun each second?
    600 million tons
  15. How much longer can the Sun continue to generate energy by nuclear reactions inits core?
    about 5 billion years
  16. What kind of chemical reaction can the sun be powered by?
    Hydrogen fusion which is a nuclear reaction
  17. What stabilizes the size by keeping gravity in and gas pressure out?
    Hydrostatic Equilibrium
  18. What sabilizes the temperature through the rate of energy production and the rate of energy release?
    Thermal Equilibrium
  19. Three methods of energy transport are?
    convection, conduction, and radiation
  20. The suns global magnetic field reverses every....?
    11 years