Asteroseismology: ESA scientists listen to the music of stars to determine their distance – GEO

With a view to the immensity of the sky, the questions multiply. It is impossible for us to grasp this vastness as a whole, to understand the structure of galaxies and the physics of stars. To solve some of these mysteries, the European Space Agency (ESA) launched the Gaia mission ten years ago.

An ambitious and unique mission dedicated to a science born in ancient times: astrometry, the measurement of the position and movement of stars. Gaia’s goal is to compile “the most complete catalog of stars in our galaxy and beyond” and has already compiled a wealth of data on the positions, distance indicators and movements of more than two billion stars.

⋙ Where does the story of Santa Claus come from?

Converting the vibration of stars into sound waves

To measure the distance to nearby stars, scientists rely on something called parallax. “Parallax is a method of measuring astronomical distances based on the angle created by a “triangulation” between the position of Gaia in space, the Sun and the star under study. The further away the star is, the more difficult the measurement is because the parallax becomes smaller with increasing distance,” explains EPFL.

IN PICTURES The most beautiful photos from the James Webb Space Telescope

But scientists from the Standard Candles and Distances department at EPFL and the University of Bologna wanted to go further and compared the GAIA data with those obtained using asteroseismology. The researchers conducted this work on more than 12,000 red giant stars.

⋙ Luc Jacquet: “I had never seen rain in Antarctica”

They studied variations in a star’s light intensity and converted these vibrations into sound waves to create a frequency spectrum. “We can use this spectrum to determine the distance to the star. This is how we get asteroseismic parallaxes. In our study, we heard the music of many stars, some of which are 15,000 light-years away!” explains Saniya Khan, lead author of the study published in the journal Astronomy & Astrophysics.

“By analyzing the frequency of these stellar vibrations, scientists can accurately determine the size of a star, just as we can estimate the size of a musical instrument based on the sound it produces – think of the different tones of a violin and a cello. ” adds Andrea Miglio, professor at the Institute of Physics and Astronomy at the University of Bologna and one of the authors of the study.

⋙ Lightless photosynthesis and the DNA printer are among the key topics of the Cambridge Horizon Scan

Asteroseismology, a discipline of the future

The data collected using asteroseismology also makes it possible to know the temperature and chemical composition of the star… before determining its distance and then comparing these results with Gaia’s parallaxes. “Only asteroseismology makes it possible to check the precision of Gaia’s parallax across the entire sky, for both weak and strong stars,” observes Saniya Khan.

⋙ Why was Louis XIII. called the righteous?

The latter believes that asteroseismology could play a crucial role even on a larger scale and in other areas of the study of the universe, such as census or the discovery of exoplanets, “which will help us determine our place in the universe.” “This will benefit a variety of areas of astrophysics,” enthuses the researcher.

Also read:

⋙ In Italy, researchers reveal an ancient astronomy manual hidden in a palimpsest

⋙ What is the difference between astronomy and astrology?

⋙ Space: The James Webb Telescope offers new explanations for the formation of planets