What do stars sound like? While sound does not travel in space because it is a vacuum, stars like the Sun still produce sounds that manifest as complex vibrations.
A team of astronomers from University of Wisconsin-Madison successfully developed a software called GYRE that can simulate the complex vibrations that stars produce.
Anyone can access and edit GYRE as an open-source program, and it plugs into another program called MESA, which facilitates the simulation of stars.
What Stars Sound Like
Telescopes can spot the complex vibrations produced by stars as fluctuations in brightness or temperature on the star's surface. What produces these subtle sounds are the nuclear furnaces inside the star, and it stirs up those complex vibrations.
When stars fuse hydrogen into heavier elements in their cores, hot plasma gas vibrates, and the star flickers. The flickering and fluctuation can help astronomers understand the structure of a star and how it changes as the star ages.
Lead researcher Jacqueline Goldstein, a graduate student at University of Wisconsin-Madison, explained that the vibration of stars depends on their structure and size.
"A cello sounds like a cello because of its size and shape," Goldstein said.
To hear the sound of stars, the stellar vibrations must be sped up by a thousand to a million times. The frequencies repeat on the order of minutes to days.
Goldstein explained that the complex vibrations produced by stars are actually called starquakes, which are quite similar to earthquakes. The field that studies these starquakes is known as astroseismology.
Software Simulates Sound Of Stars
In her research, Goldstein studied stars that are bigger than the sun. She explained that these are the stars that explode and make black holes and neutron stars, and these stars also form planets and new life.
Goldstein said she wanted to understand how these stars work and how they affect the evolution of the universe. To do that, she studied the connection between the structure of stars and their vibrations.
Along with professors Ellen Zweibel and Rich Townsend, Goldstein developed the GYRE program linked to MESA to simulate diverse stars and their frequencies.
The team of researchers led by Goldstein constructed models of various types of stars to see how their vibrations would appear, and then they would check if the simulation resembled the reality.
As Goldstein compares the simulation to reality, she is able to refine her model and improve the process of how scientists can study the surface of stars to survey the subtle sounds they produce.
Goldstein explained that if the predicted vibration patterns and the observed vibration patterns are the same, it provides insight into the inside of the star.
However, if the predicted vibration patterns and the observed vibration patterns do not match, it gives scientists information that they must improve the simulations and check again.
The Search For Exoplanets
The research accomplished by Goldstein and the professors who helped her is supported by the data collected by planet hunters.
In fact, with the help of NASA's exoplanet hunter telescope called TESS, scientists are able to see whether all the stars in the neighborhood are pulsating or not. If the stars are pulsating, Goldstein and her colleagues will be able to study what's happening beneath the surface.
With that, Goldstein is now developing a new version of GYRE that uses data collected by the TESS telescope. She will be able to simulate an entire stellar orchestra using this powerful tool.
