“New research undertaken at Northumbria University, Newcastle shows that the sun’s magnetic waves behave differently than currently believed.
Their findings have been reported in Nature Astronomy.
After examining data gathered over a 10-year period, the team from Northumbria’s Department of Mathematics, Physics and Electrical Engineering found that magnetic waves in the sun’s corona – its outermost layer of atmosphere – react to sound waves escaping from the inside of the sun.
These magnetic waves, known as Alfvénic waves, play a crucial role in transporting energy around the sun and the solar system. The waves were previously thought to originate at the sun’s surface, where boiling hydrogen reaches temperatures of 6,000 degrees and churns the sun’s magnetic field.
However, the researchers have found evidence that the magnetic waves also react – or are excited – higher in the atmosphere by sound waves leaking out from the inside of the sun.
The team discovered that the sound waves leave a distinctive marker on the magnetic waves. The presence of this marker means that the sun’s entire corona is shaking in a collective manner in response to the sound waves. This is causing it to vibrate over a very clear range of frequencies.
This newly-discovered marker is found throughout the corona and was consistently present over the 10-year time-span examined. This suggests that it is a fundamental constant of the sun – and could potentially be a fundamental constant of other stars.
The findings could therefore have significant implications for our current ideas about how magnetic energy is transferred and used in stellar atmospheres.”
Image: The Sun’s corona – its outermost layer of atmosphere. Credit: Northumbria University, Newcastle