This is a fun activity that calls for matching up pairs of images of the Sun. This can be done online or printed out and done in a class or small group setting. Each pair was taken about the same time on a given day, but the pairs were taken from five different days over the past few years. The black and white images reveal areas of strong magnetic activity on the Sun's surface, in which the black indicates one pole of magnetic attraction and white the other. The yellow images show activity above the Sun's surface in extreme ultraviolet light in which areas of more intense activity appear lighter. These regions of intense activity, where magnetic forces are connecting, breaking apart and reconnecting, are often the sources of solar storms. Many of these areas would appear as sunspots in "white light" or simply filtered images of the Sun.
You will find that the magnetic images match up very closely with the ultraviolet images. See if you can find the pairs of images taken on the same days.
(pdf version of this activity)
After you have completed the activity, download this movie (available formats: MPEG (2.6M), large Quicktime (1.3M) and small Quicktime (382k)) to see how active regions (seen here by SOHO in a different wavelength of UV light) and magnetic areas match up as the Sun rotates.