Asteroseismology:
Asteroseismology is the study of oscillations in stars. Stars have many resonant modes and frequencies, and the path of sound waves passing through a star depends on the speed of sound, which in turn depends on local temperature and chemical composition. Because the resulting oscillation modes are sensitive to different parts of the star, they inform astronomers about the internal structure of the star, which is otherwise not directly possible from overall properties like brightness and surface temperature. [Wikipedia]
Noted in “Gaia telescope’s new map of the Milky Way will let us rewind time,” Alex Wilkins, NewScientist (18 June 2022):
One particular type of tsunami-like vibration that changes a star’s shape, known as a starquake, was detected on some stars when it shouldn’t have been possible according to current theories. “Gaia is opening a goldmine for ‘asteroseismology’ of massive stars,” said Conny Aerts at KU Leuven in Belgium in an ESA statement.
