what's the Sun's magnetic field like?

This is a movie from the MDI instrument on SOHO. It shows the magnetic field on the surface of the Sun. Black and white are positive and negative polarity. See how the magnetic field is changing all the time. The large areas of black and white are where the active region and sunspots are.

The Sun’s magnetic field is much stronger than the Earth’s. We have discovered that it can be over 4000 times as strong in sunspots like the one pictured here. A compass would practically fly out of your hand!

Sometimes the magnetic field breaks through the Sun’s surface with spectacular effects. This diagram shows two sunspots: one where the field leaves the surface of the Sun and one where it re-enters the surface.

At other times even more spectacular effects are caused by the Sun’s magnetic field. This picture shows a prominence. The magnetic loop towers thousands of kilometres above the Sun’s surface. This loop rises above the Sun’s surface to about the same distance as the Moon is from Earth.

The Sun has a 'large scale' magnetic field like the Earth , but the north and the south magnetic poles change over every 11 years.

That's another feature of the solar cycle

The Sun also has a 'small scale' magnetic field covering its entire surface, like lots of smaller bar magnets . This 'small scale' magnetic field keeps changing and is completely refreshed every 48 hours.