An audio simulation of the gentle twinkling of a star sounds much more menacing than you think
- Northwestern researchers have created the world's first audio simulation of twinkling stars.
- They did this by converting simulations of gas waves produced inside stars into sound waves.
Ever wonder if the twinkle of a star sounds as pleasant as the famous nursery rhyme?
A team of researchers took this question to the next level by creating a model of what it could sound like and the results are fascinating — and a little unsettling.
To do so, the Northwestern University-led team first created 3D simulations of the churning of gas that occurs deep within a star, similar to convection on Earth's surface, according to the study published in Nature Astronomy.
As a result of this movement of energy, waves of gas form and "launch" to the star's surface. This helps produce a slight "twinkling" light effect, according to a press release from Northwestern.
They then converted these heat-produced waves into sound waves — a process known as sonification — to produce an "eerily fascinating" recreation of what this flickering phenomenon should sound like. The frequencies of the star simulations were modified to reach a range suitable for human hearing.
The researchers released a sample of the sound. Anders described it as a "jackhammer mixed with the static you hear between radio stations" combined with "a siren and a low, oscillatory rumble behind it."
"The more massive the star, the deeper (more bass) the sound of the siren, and the background rumble is easier to hear," Anders said.
"I think we were expecting it to sound unpleasant, but we were surprised by the sounds we heard!" Evan Anders, who led the study, explained to Insider in an email. Anders said that converting the waves to sound allowed the team to understand "how strong the 'siren' and 'rumble' sounds were compared to each other" in a way that just simply looking at data points could not.
The team also used songs like "Twinkle Twinkle, Little Star" and Gustav Holst's "Jupiter," and modeled how they would sound as waves produced by small, medium, and large stars. Because the stars favored certain wavelengths, the smaller stars retained the higher-pitched parts of the tune, whereas the larger stars kept the low, bellowing noises. This experiment allowed the team to understand how stars change waves that move through their interiors.
"Just like different instruments favor different pitches and resonances of waves, so do stars, and just like instruments have a timbre, the waves in stars have a timbre," Anders said of the sonification process.
The twinkling effect portrayed by the models in the study differs from the "twinkling" people observe on the ground due to the earth's atmosphere bending its light.
Anders explained to Insider that many types of waves produce inherent twinkling in stars (the field of asteroseismology is dedicated to observing them). Still, the specific kind of waves produced by the core activity simulated by the team is currently imperceptible to the human eye. If scientists can one day observe this flickering with a high-powered telescope, it can help better inform of the inner workings of stars, gigantic and small.
The team took three years to complete the research, Anders said, and he hopes that the study will give scientists a better visual of star cores, whose size determines a star's life cycle and where elements that support life are forged.
"There's a lot of work to be done to characterize all of these waves, but we can really learn a lot about stars, and stars are the building block of many of the structures we see when we look out into the universe," Anders said.