The Sun is a large ball of ionised helium and hydrogen gas. All parts of the Sun do not rotate at the same speed. The equator of the Sun rotates the fastest – one rotation each twenty five days compared to one rotation per thirty five days at the poles. Because the Sun is made up of ionised gas, it generates a magnetic field. Because all parts of the Sun do not rotate at the same speed, the magnetic field is not fixed. As the Sun rotates, the magnetic field becomes twisted and contorted. At times, the magnetic field can burst out of the Suns surface and enter the sun again at some other points. These are called sunspots. Sunspots come in pair, each pair consisting of a magnetic north pole and a magnetic south pole.
The temperature in the area of the sunspot is much lower than surrounding areas, and the sunspots are darker. Charged particles are accelerated in the field and can produce massive solar flares, expelling large amounts of gas. Some of these may cause disruption to electricity supplies and satellite communications on Earth.
Sunspots occur in an eleven year cycle, so that the is a peak of sunspots every eleven years or so. The power produced by the Sun also varies slightly, which can result in variations in the Earths weather.