The Death of the Sun!

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The Death of the Sun!
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Type of Death

• What a star becomes when it dies depends on the
  mass left when all possible nuclear fuels are
  exhausted and the star has lost some of its
  original mass by ejecting it
• M lt 1.4 M -----gt white dwarf/planetary nebulae
• 1.4 M ltM lt 3 M --gt neutron stars/pulsars
• M gt 3 M ----gt supernovae/black holes

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Stars like the Sun

• After a star like the sun exhausts its nuclear
  fuels, it loses its outer layers as a "planetary
  nebula" and leaves behind the remnant "white
  dwarf" core. The white dwarfs are extremely small
  stars -- they are the bare remnant cores of stars
  after they have gone through all of their
  lifetimes.

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Watch our sun die!
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Planetary Nebula

• Planetary nebulae were misnamed because of their
  round shapes and greenish colors (caused by an
  oxygen emission line) -- as in the bright central
  part of the one to the right. They actually have
  nothing to do with planets. A planetary nebula is
  a shell of hot gas expanding away from a small,
  very hot star (a white dwarf - you can just see
  it near the center).

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• Planetary nebulae take many wonderful and
  beautiful forms. However, they all are created
  through similar processes. One step is when tiny
  dust grains form near the surface of the star and
  the pressure of the light photons on them expels
  them, carrying some of the gas along.

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Here is a simulation of how it would look - the
diameter of the field is about 10 times the size
of the orbit
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A very young planetary nebula. The optical image
shows shadowing by a disk, waves from pulsed mass
loss, and "searchlights" of light. The infrared
image on the right shows molecular hydrogen (red)
and the denser material that shapes the visible
searchlights.
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This animation shows the overall collapse of the
red giant accompanied by the ejection of material
that expends into the "Helix", a planetary nebula
(From NASA, STScI).
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The sun will end its life as a white dwarf.
http//ircamera.as.arizona.edu/NatSci102/lectures/
whitedwrf.htm