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- SUNíS MAGNETIC FIELD
-
- The Sun's magnetic field is very complex. The polarity slowly changes every 11 years and this is accompanied by
- increased sunspot activity. On Earth this is seen as increased auroras. The next peak in sunspots will be in
- 2000/2001, which accordingly should be a good year for auroras.
-
- Changes in the Sun's magnetic field affect the Sun's brightness and also the Earth's temperature. These pictures are
- provided by MDI and EIT.
-
- Research on other sun-like stars has shown that they too have similar changes in magnetism. For example the star 107
- Piscium had a magnetic peak in 1984 and a low in 1991. As the magnetic field diminished, light went down 0.6
- percent. This change is much greater than the short-term variation in the Sun's light. In the long run, the brightness of
- our Sun varies too (since the 18th century the Sun's brightness has increased by 0.4 percent) and this has been used as
- one explanation of both the ice ages and the greenhouse effect.
-