Mercury,
July/August 2002 Table of Contents
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Courtesy
of the Hubble Heritage Team (AURA/STScI/NASA).
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by
James B. Kaler
The
interplay of light and atoms paints the beautiful palette of planetary
nebulae.
When
I was about 13 years old, I pointed my terribly aberrated 3-inch
telescope between Beta and Gamma Lyrae. To my amazement, I actually
found the Ring Nebula (M57). Although I had seen pictures, the memory
of that ghostly smoke ring still holds more fascination for me than
the Hubble pictures do today. Shortly thereafter I located the next
best of the backyard planetary nebulae, the Dumbbell (M27). No other
planetaries seemed to be within my poor telescopes reach,
but no matter, my interest in these marvelous creations had begun.
Even
as a teenager I knew that the nebulae were somehow illuminated by
their central stars, but I was in college before I learned how that
feat is actually accomplished. Textbooks often slough off the explanation
by saying that the nebulae are lit by some kind of fluorescence,
and let it go at that, as if serious physical descriptions are inherently
uninteresting. Part of the joy of astronomy, however, is not simply
seeing the sights, but in understanding why the sights are there
in the first place. So come along on a trip to the inside of a planetary
nebula and see what really happens as light and atoms violently
interact to create some of the loveliest objects in the night sky.
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