Sunspots: Cool, Dark and
are relatively dark patches on the Sun’s
bright surface. They are regions of concentrated
magnetic fields that
can last from several hours to several months.
Sunspots appear dark because they’re
cooler (4000°C) than the plasma surrounding
them (6000°C). They tend to develop
in groups, with some groups covering areas
20 times the diameter of Earth.
Sunspot’s magnetic field is similar
to a horseshoe magnet lying below the
Sun’s surface. A Sunspot group
has a “north” and “south” magnetic
pole (like Earth does).