- The magnetic field of our Sun behaves quite differently than presently believed.
- The sound waves originating from the Sun’s internal acoustic oscillations affect the magnetic waves at its surface.
- These waves make the entire corona vibrate in a collective manner at a specific frequency range.
Most stars possess complex magnetic fields that play a crucial role in energizing and structuring their atmosphere. However, scientists haven’t been able to completely decode the nature of these fields.
In the 1970s, astronomers observed a phenomenon called alfvénic fluctuations and since then it has been recorded regularly in the solar wind. These alfvénic waves are responsible for transferring energy along magnetic fields, heating plasma and accelerating stellar winds.
Recently, researchers at Northumbria University, Newcastle reported that magnetic waves of our Sun behave differently than presently believed. They examined data collected over the last decade and discovered that magnetic waves in the Sun’s corona — an aura of plasma that surrounds the star — are affected by the sounds waves coming from the Sun’s interior.
A Unique Marker On The Sun’s Magnetic Waves
Alfvénic waves were previously estimated to arise at the surface of the Sun, where temperatures reach approximately 6,000 kelvins and magnetic fields get churned by boiling hydrogen.
The team discovered that magnetic waves react with sound waves higher in the Sun’s atmosphere. These sound waves affect magnetic waves in a unique way: they make the entire corona of the Sun shake in a collective manner. The corona vibrates over a specific frequency range.
Researchers found this effect consistently over the 10-year data. This could potentially be a new fundamental constant of our Sun, as well as of other stars.
The energy originating from alfvénic waves heats up the Sun’s corona to over one million kelvins, much hotter than the Sun’s surface. They also heat and accelerate strong solar winds that travel millions of miles into outer space, affecting the atmosphere and magnetic fields of planets and stars.
Sun’s Corona | Image Credit: NASA
As per previous studies, the boiling hydrogens on the Sun’s surface play a major role in exciting magnetic waves. The new study has made it clear that we have been interpreting it all wrong. It is the Sun’s internal acoustic oscillations that excite magnetic waves.
This might lead to new techniques of analyzing and classifying the behavior of stars under this distinctive marker, and help us better understand how magnetic energy is transmitted in stellar atmospheres.