Sun's magnetic waves can be influenced by sound waves leaking from the Solar System's star

Sun's magnetic waves are crucial for transportation of energy around the Sun, as well as the solar system

The Sun's magnetic waves behave in a different manner than believed and can be 'excited' by the sound waves leaking out from the Sun, claims a new study by researchers at Northumbria University, Newcastle.

The Sun's corona is the outermost part of its atmosphere, and is about one hundred times hotter than the surface of the Sun. The corona remains hidden due to the bright light of the Sun's surface and can only be seen using special instruments.

The magnetic waves originating in the Sun are known as Alfvénic waves. They are low-frequency travelling oscillation of the ions and the magnetic field, and are responsible for the transportation of energy around the Sun as well as the solar system.

These waves are named after Hannes Alfvén who in 1942 proposed the existence of electromagnetic-hydrodynamic waves able to carry energy from Sun's photosphere to heat up the corona and the solar wind.

According to Alfvén, the Sun has all the necessary conditions to support these waves. In 1970, Alfvén was awarded the Nobel Prize in Physics for his discovery.

Scientists have long believed that Alfvénic waves originate only at the surface of the Sun (after being excited by the boiling hydrogen). However, the results of the new study suggest that these waves can also be excited higher in Sun's atmosphere by sound waves leaking out from the inside of the Sun.

In the new study, the researchers collected data over a 10-year period and found that the sound waves coming from inside of the Sun leave a distinct marker on the magnetic waves. This finding suggests that sound waves cause the entire corona to shake or vibrate in a collective manner over a very distinct range of frequencies.

The presence of the marker throughout the corona, and consistently over the 10-year period, suggests that it could be a fundamental constant of the Sun and also of other stars.

Scientists believe the results could have implications for our current understanding of the transfer of magnetic energy in stellar atmospheres.

"The discovery of such a distinctive marker - potentially a new constant of the Sun - is very exciting," said Dr Richard Morton, senior lecturer at Northumbria University and the lead author of the study paper.

"Our evidence shows that the Sun's internal acoustic oscillations play a significant role in exciting the magnetic Alfvénic waves. This can give the waves different properties and suggests that they are more susceptible to an instability, which could lead to hotter and faster solar winds."

The findings of the study are published in journal Nature Astronomy.