This took roughly 4.5 billion years to accomplish. When the hydrogen is exhausted, the Sun's temperature at the surface will begin to cool and the outer layers will expand outward to near the orbit of Mars. Sunspots are areas where the magnetic field is about 2,500 times stronger than Earth's, much higher than anywhere else on the Sun. Because of the strong magnetic field, the magnetic pressure increases while the surrounding atmospheric pressure decreases. This in turn lowers the temperature relative to its surroundings because the concentrated magnetic field inhibits the flow of hot, new gas from the Sun's interior to the surface.
Sunspots tend to occur in pairs that have magnetic fields pointing in opposite directions.
A typical spot consists of a dark region called the umbra , surrounded by a lighter region known as the penumbra . They occur near sunspots, usually at the dividing line between areas of oppositely directed magnetic fields. Hot matter called plasma interacts with the magnetic field sending a burst of plasma up and away from the Sun in the form of a flare. Solar flares emit x-rays and magnetic fields which bombard the Earth as geomagnetic storms . If sunspots are active, more solar flares will result creating an increase in geomagnetic storm activity for the Earth.