The solar theory group at St Andrews University has won nearly Pounds 1 million over four years from the Particle Physics and Astronomy Research Council, the largest award to go to a theory group.
The group creates theoretical mathematical models to explain why magnetism causes profound physical effects on the sun, such as solar flares and sunspots. This work not only increases basic understanding, but also provides theoretical back-up for space missions such as Soho, the Solar and Heliospheric Observatory, laun- ched last December.
Magnetic fields are concentrated at various points on the sun's surface, and the flow of electric currents causes the unique effects of solar flares and sunspots. The sun's outer atmosphere, or corona, is hotter than the surface, with a temperature of 2 million degrees centigrade, but can support cool, dense clouds suspended in the corona by magnetic fields. The corona can suddenly erupt into solar flares which may last for only a few minutes. Sunspots are the visible effect of cool areas, where the magnetic fields are concentrated on the sun's surface, and follow an 11-year cycle.
These magnetic blemishes remain mysterious, despite having been observed from earth for more than 2,000 years.
The group is also studying the new subject of helioseismology, which is building up information on the structure of the sun's interior. Continuous wave motions from within the sun cause the gases at the surface to move up and down, altering their temperature and brightness.
Studying these wave patterns gives information on the variations of temperature and composition of the sun's interior, and solar observatories have been set up round the world to monitor the oscillations 24 hours a day, while Soho views them from space.