Blue Herald
20
Apr
Sun’s Atmosphere Sings
by Jim Swanson • 9:46 am

A brief respite from the hard news of war and politics. A little bit of science.

Astronomers have recorded heavenly music bellowed out by the Sun’s atmosphere.

Snagging orchestra seats for this solar symphony would be fruitless, however, as the frequency of the sound waves is below the human hearing threshold. While humans can make out sounds between 20 and 20,000 hertz, the solar sound waves are on the order of milli-hertz–a thousandth of a hertz.

The study, presented this week at the Royal Astronomical Society’s National Astronomy Meeting in Lancashire, England, reveals that the looping magnetic fields along the Sun’s outer regions, called the corona, carry magnetic sound waves in a similar manner to musical instruments such as guitars or pipe organs.

Making music

Robertus von Fay-Siebenburgen of the Solar Physics and Space Plasma Research Center at the University of Sheffield and his colleagues combined information gleaned from sun-orbiting satellites with theoretical models of solar processes, such as coronal mass ejections.

They found that explosive events at the Sun’s surface appear to trigger acoustic waves that bounce back and forth between both ends of the loops, a phenomenon known as a standing wave.

“These magnetic loops are analogous to a simple guitar string,” von Fay-Siebenburgen explained. “If you pluck a guitar string, you will hear the music.”

In the cosmic equivalent of a guitar pick, so-called microflares at the base of loops could be plucking the magnetic loops and setting the sound waves in motion, the researchers speculate. While solar flares are the largest explosions in the solar system, microflares are a million times smaller but much more frequent; both phenomena are now thought to funnel heat into the Sun’s outer atmosphere.

Complete Feature story at YAHOO!


Comments OffMeta InfoEmailPrint+Share

Related:


Loading...