It is well known that sound cannot propagate in vacuum as it requires a medium for its transmission. Sounds propagate as longitudinal waves in solids and fluids and also as a tranverse wave in solid structures. But scientists have been able to overcome this limitation as they have developed an innovative way for interpreting the signals which have been emitted by cosmos.
Researchers at University of Wisconsin-Madison have separated a different type of resonance which are caused by stars. These vibrations are actually variations in the temperature and the brightness of stars. Very powerful telescopes can spot these vibrations and then recreate the sounds of the stars with the help of computer simulations.
Jacqueline Goldstein, a graduate student in astronomy at University of Wisconsin-Madison said that a cello’s sound is because of its shape and size, similarly the vibrations of the stars are also dependent on their size and composition. Goldstein studies the connection between the structure of stars and their vibrations with the help of the software which simulates many stars and their frequencies. After comparing the simulations to the real stars, she can improve her model and make necessary changes.
For human beings to hear the sounds, the speed of the vibrations have to be increased by thousand to million times, besides repeating the frequencies from minutes to days. These are known as starquakes after their seismic variants on Earth and the field of study is called as astroseismology.
After the fusion of hydrogen in stars to heavier elements in the star cores, plasmic gas vibrates and hence the stars flicker. Researchers can know about the structure of stars through these fluctuations and also the changes which may occur in the star with the passage of time.
Goldstein studies those stars which are bigger than the sun as these are the ones which explode and lead to the formation of black holes, neutron stars and the heavy objects in the cosmos. Scientists want to study about the functioning of these stars and how they make an impact in the expansion and evolution of the universe.
With the help of professors of astronomy, Rich Townsend and Ellen Zweibel, Goldstein has created a computer software named GYRE which is plugged into the simulation software for stars, MESA. These softwares make it possible to develop models of different kinds of stars and observe their vibrations as they may appear to astronomers.
Since, GYRE and MESA are open source programs, they can be accessed freely by the scientists and modified. Goldstein is currently making a modified version of GYRE to take advantage of the data obtained by TESS.