Helioseismology

The study of the interior of the Sun by measuring waves that ripple across its surface. The waves are generated by the motions of giant bubbles of hot gas in the Sun's outer layer, known as the convective zone, which extends about a third of the way from the surface to the Sun's center. The waves can travel all the way around the Sun, causing "jiggles" when they reach the surface. The individual waves can reveal details about the Sun's structure, interior temperatures, composition, and more. Astronomers measure the waves through tiny changes in the motion of the Sun's surface toward or away from Earth. Studying similar waves on other stars is known as asteroseismology.