solar activity cycle

Take a look at these two pictures. The picture on the left shows the X-ray radiation from the Sun. The picture on the right is a normal visible light photograph. See how the bright parts in the X-ray image, called active regions, correspond to the places where the sunspots are. To see the movie that these pictures were captured from click on the movie option to the right.

The picture shows how the solar activity (in this case, the X-ray brightness of the corona) changes during the solar cycle. The image on the far right was taken at solar minimum and the other images were taken at 6-monthly intervals up until solar maximum, shown in the front image to the left.

The front left hand image shows solar maximum

The Sun also looks very different in the ultraviolet at solar minimum (1996) (left hand side) and solar maximum (1999) (right hand side). Just see how many active regions there were in 1999!