Music of the sun recorded by scientists

The sun has been the inspiration for hundreds of songs, but now scientists have discovered that the star at the centre of our solar system produces its own music.

By Richard Gray, Science Correspondent

9:00PM BST 19 Jun 2010

Astronomers at the University of Sheffield have managed to record for the first time the eerie musical harmonies produced by the magnetic field in the outer atmosphere of the sun.

They found that huge magnetic loops that have been observed coiling away from the outer layer of the sun's atmosphere, known as coronal loops, vibrate like strings on a musical instrument.

In other cases they behave more like soundwaves as they travel through a wind instrument.

Using satellite images of these loops, which can be over 60,000 miles long, the scientists were able to recreate the sound by turning the visible vibrations into noises and speeding up the frequency so it is audible to the human ear.

Professor Robertus von Fáy-Siebenbürgen, head of the solar physics research group at Sheffield University, said: "It was strangely beautiful and exciting to hear these noises for the first time from such a large and powerful source.

"It is a sort of music as it has harmonics.

"It is providing us with a new way of learning about the sun and giving us a new insight into the physics that goes on at in the sun's outer layers where temperatures reach millions of degrees."

The coronal loops are thought to be involved in the production of solar flares that fling highly charged particles out into space, creating a phenomenon known as space weather.

When the sun's activity, and thus solar flare production, increases, the resulting "space storm" can have catastrophic results here on earth, destroying electronic equipment, overheating power grids and damaging satellites.

Nasa warned last week that the sun's activity is starting to increase following an extended period of low activity and is on course to throw out unprecedented levels of magnetic energy into the solar system by 2013.

Professor Fáy-Siebenbürgen said that studying the "music of the sun" would provide new ways of understanding and predicting solar flares before they happen.

The coronal loops vibrate from side to side because they are "plucked" rather like guitar strings by the blast waves from explosions on the surface of the sun.

The scientists also found the loops vibrate backwards and forwards in a way that mimics the acoustic waves in a wind instrument.

Scientists cannot directly record the sound produced in the Sun's atmosphere because sound cannot travel through the near vacuum of space.

They are, however, able to use visual observations of the frequency at which the coronal loops vibrate to recreate the sound back here on Earth.

Professor Fáy-Siebenbürgen's research has been revealed as the University of Sheffield launches a new project, called Project Sunshine, aimed at finding new ways to harness and understand the power of the sun.

He said: "These loops are oscillating like the strings on a guitar or the air in a wind instrument. Over time the waves die away and that is telling us new things about the physics in the sun's atmosphere."