First-ever close-up of Sun’s south pole reveals a speedy surprise

By Dean Murray

Scientists have revealed their analysis of the first close-up view of the Sun's south pole.

ESA's spacecraft Solar Orbiter had its first clear view of the region in March.

Analysis of the data has now been published, which reveals magnetic fields speeding toward the pole much faster than expected—reshaping key ideas about the Sun’s powerful cycles.

The research investigated a refined picture of the supergranulation and magnetic network of the Sun at the south pole for the first time.

Supergranules are cells of hot plasma, about two to three times the size of Earth, which densely cover the surface of the Sun.

The study in the journal Astrophysical Journal Letters, led by researchers from the Max Planck Institute (MPS) in Germany, analysed measurements that provide information about the direction of plasma flows and the magnetic field on the solar surface.

To the surprise of the researchers, the magnetic field is seen to drift toward the poles at approximately 10 to 20 metres per second, on average, almost as fast as their counterparts at lower latitudes.

Previous studies based on the ecliptic-plane observations have seen much slower drifts of the magnetic field near the high polar latitudes. Their motion offers important clues about the Sun’s global plasma and magnetic field circulation.

A MPS statement said: "It is still unclear whether the Sun's global “magnetic conveyor belt” does truly not slow down near the poles.

"The data now published only show a brief snapshot of the entire solar cycle. Further observational data, ideally covering longer time periods, are needed."