However, there are still substantial amounts of energy in the Near Ultraviolet and Infrared portions of the energy spectrum. Because the Sun is a large sphere of rotating gas with its equator rotating more rapidly than the poles there are constant changes and fluctuations as its gaseous contents mix and move. The rotation period is about 24 days at the equator and about 34 days at the poles. This differential rotation is frequently used to explain why the Sun displays changes in its solar activity. One of the major visible features of the mixing action caused by the rotational differences is the sunspot.
Sunspots are relatively cool regions within the visible surface of the sun.
They appear dark against the hotter and brighter surrounding gas. The gas within a sunspot is relatively cool because it radiates more energy in the non-visible spectrum than it receives. The sunspot remains relatively cool because the strong magnetic field that accompanies it confines the gas within the sunspot so that it cannot mix with the hotter gases surrounding it. Consequently, sunspots, their magnetic fields, flares, and solar activity in general are very closely related so to monitor and predict solar flares we should watch and study the activities of their companion phenomenon, sunspots. And, it turns out, sunspots are fairly easy to study and they are cyclic in nature .