About every eleven years somewhere deep in the Sun a special prosess occurs, and a few
years latter the visible surface becomes marked with black spots which are called sunspots.
No one knows exactly how the process works, but we do know that sunspots are produced
by strong magnetic fields that are created in the interior. Sunspots and their magnetic effects
are among the most fascinating features on the Sun. In spite of the fact that we do not really
know what makes sunspots erupt from the interior, there is much that we do know about
them. Sunspots have been studied longer than any other feature of the Sun.
Sunspots were known long before the invention of the telescope, because they often
grow to sufficient size to be visible to the naked eye. Sunspot appearances are recorded
throughout history, dating back to Theopharastus, a pupil of Aristotle, in the fourth century
B.C. Chinese astronomers also recorded the appearance of naked-eye sunspots, and have left
a lot of written records about their observations. At the time of the invention of the telescope,
their existence was well known, but they were not believed to be the
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