Heavenly Solar Music
Photo of magnetic solar coronal loops via Eureka Alert by TRACE
Musical sounds created by longitudinal vibrations within the Sun’s atmosphere, have been recorded and accurately studied for the first time by experts at the University of Sheffield, shedding light on the Sun’s magnetic atmosphere.
Using state-of-the-art mathematical theory combined with satellite observations, a team of solar physicists from the University have captured the music on tape and revealed the harmonious sounds are caused by the movement of giant magnetic loops in the solar corona -the outermost, mysterious, and least understood layer of the Suns atmosphere. Most importantly, the team studied how this sound is decaying, giving an unprecedented insight into the physics of the solar corona.
High-resolution images taken by a number of satellites show that the solar corona is filled with large banana-shaped magnetic structures known as coronal loops. It is thought that these giant magnetic loops, some of them over a few 100,000 km long, play a fundamental role in governing the physics of the corona and are responsible for huge atmospheric explosions that occur in the atmosphere, known as solar flares.
These giant coronal loops have also 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). With the length and thickness of the string fixed, the pitch of the note is determined by the tension of the string and the tone is made up of the harmonics of the modes of oscillation. In this sense, the solar atmosphere is constantly pervaded by the music of the coronal loops.