For the first time you can listen to the music the stars make, thanks to advances in science and technology, and a little bit of music magic courtesy of famed producer Brian Eno.
The universe is not silent. Stars make up a cosmic orchestra, performing a concert that never stops. All stars produce infrasound acoustic waves, too low-frequency for a human ear to hear, that luckily can be picked up by telescopes. We think of sound as something that makes noise, but in pure physics terms, sound is just a vibration going through matter.
Because, like instruments, stars are not solid all the way to their core, the sound waves get trapped in the outer layers and bounce around inside. This makes the star vibrate, which in turn makes it dim and brighten, which we can detect with telescopes and reconstruct the sound produced by these vibrations.
In this cosmic orchestra, the biggest stars are the bass or oboe, producing the lower, deeper sounds, while the smaller ones are the higher-pitched flute or violin. It’s these infrasound acoustic waves, computed by astrophysicist Dr Garik Israelian and arranged by Brian Eno, that are sped up so we can hear them. You can listen to them right here, created as the “Starsounds” project for this year’s Starmus Festival.
The Starmus Festival, set up by Dr Israelian and astrophysicist and legendary Queen guitarist Dr Brian May, is an annual celebration of stellar science and space exploration, music, and art, with esteemed patrons from both fields including the late Professor Stephen Hawking and Peter Gabriel.
The festival's latest project, Starsounds, has an incredible pedigree. Based on Dr Israelian’s lecture “Our Acoustic Universe” featured in the Starmus-published book 50 Years of Man in Space, Brian Eno arranged the Israelian's vast "star sounds" library into a composition that can be heard by humans by speeding up the low-frequency acoustic waves. Paul Franklin and Oliver James of DNEG, the Oscar-winning visual effects studio, then created accompanying images based on star waveforms and images of the Sun. The result is a mesmerizing video that lets us both listen to and "see" a full stellar symphony.
Of course, observing these vibrations isn't just for the purpose of making music. Studying sound waves in stars helps inform astronomers about their size, age, and internal structures, much like how geologists gauge the interior of Earth from seismic waves and earthquakes. This, in turn, teaches us more about any planets orbiting these stars. NASA's planet-hunting missions Kepler and TESS are both sensitive enough to detect stellar vibrations and so use this technique, and the more we know about the stars in the universe, the more we can find out about the planets that orbit them.