The study of stellar oscillations to infer internal properties like age and structure.Asteroseismology is the study of the natural oscillations of stars. Just as seismologists use earthquakes to probe Earth's interior, astronomers use stellar vibrations to infer the internal structure, composition, and evolution of stars. These oscillations, often caused by turbulent convection or magnetic activity, create subtle periodic changes in a star's brightness or surface motion. By analyzing these pulsations, scientists can determine a star's mass, radius, age, and even its internal rotation profile, turning distant points of light into objects with a known 'heartbeat'.
The field began in the 1960s with observations of the Sun's five-minute oscillations, but it expanded to other stars in the 1980s and 1990s with the advent of space missions like CoRoT and Kepler, which provided continuous, high-precision photometry.
Stars vibrate in specific resonant modes, similar to how a bell rings at particular frequencies. The frequencies of these modes depend on the star's internal properties—denser or hotter regions transmit sound waves faster, altering the pattern of oscillations. Telescopes measure tiny brightness variations (photometry) or Doppler shifts in spectral lines over time. The resulting frequency spectrum is matched against theoretical models to deduce the star's internal structure. For red giants, the oscillation patterns are especially rich, allowing precise age estimates that are otherwise difficult to obtain.
Asteroseismology is used to characterize exoplanet host stars, providing accurate stellar radii and ages that are critical for interpreting planetary properties and understanding planetary system evolution.
The Sun oscillates with a dominant period of about five minutes, and these oscillations were first detected in the 1960s but were initially dismissed as noise in the solar atmosphere.







