Music from the Sun

Magnetic coronal loops form a solar harmonica with temperature over a million degrees. The average length of these loops are a few 100,000 km (left).
Still image from a video from the Transitional Region and Coronal Explorer (TRACE), showing eruptions from the solar corona (right).

WHO knew that the Sun was so musical? For the very first time, harmonious sounds that were created by longitudinal vibrations within the Sun's atmosphere have been recorded and studied by the experts at the University of Sheffield (U of S). With the aid of the mathematical theory, combined with steadfast satellite observations, a team of distinguished solar physicists from the U of S has captured this distinct solar music on tape which many are hoping would shed some light on the Sun's magnetic atmosphere as well as into the physics of solar corona. It is believed that the harmonious sounds in the Sun are caused by the movement of giant magnetic loops in the solar corona, the outermost, mysterious and least understood layer of the Sun's atmosphere. But what is the process of this mysterious yet melodic solar auditory composition? It's been found, after studying high-resolution satellite images of the sun, that the solar corona is filled with large banana-shaped magnetic structures which are known as coronal loops. And it is believed that these giant magnetic loops (some of which are over a few 100,000 km long), play a crucial role in governing the physics of the corona and are also responsible for huge atmospheric explosions that occur in the solar atmosphere, which are traditionally known as solar flares. And it is these giant coronal loops that have been observed to undergo periodic (oscillatory) motion, which can be thought of as someone plucking a guitar string (transversal oscillations) or blowing the wind-pipe instrument (longitudinal oscillations). And in these ways, the solar atmosphere is constantly encompassed by the music of the coronal loops.
Led by Prof. Robertus von Fay-Siebenburgen of Dept. of Applied Mathematics, U of S, the scientists believe that this coronal music will usher further breakthrough into the understanding of one of the crucial yet unresolved problem of modern astrophysics. And that is the heating process of solar and tellar coronal plasmas. Scientists are also hoping that this discovery will pave the way towards the understanding of this following crucial question. Are there millions of localized magnetic explosions releasing the energy necessary to maintain the corona at millions of degrees or is the physics related to the numerous waves propagating from the internal regions of the Sun toward its outer regions, reaching even space around the Earth's atmosphere?
It is important to note here that this is second solar related breakthrough made by the scientists from U of S. The way the solar corona is heated to the temperatures of over a million degrees, until very recently, remained an ancient puzzle of astro-physics, since this particular regions of the Sun is much further away from the centre of energy production than the underlying solar surface. But Prof. Siebenburgen's team solved this mystery and revealed that Transition Region Quakes, described by the experts as "mega tsunamis" actually power the lower base of the solar corona. And this month's discovery which was presented in front of an audience comprised of MP's from both House of the Commons as well as House of the Lords along with senior scientists from Royal Society is hailed as a pioneering one. In his own words, Prof. Siebenburgen said, "The results of our latest coronal research, presented in the Parliament at Westminster, allow us to gain a fundamentally new insight into the fascinating but at the same time very mysterious solar atmosphere". Now, the next stop for the scientists is to develop cutting edge numerical modeling that will be able to give further insight into the sub-resolution properties of coronal loops.

The contributor is a freelance science writer.