What is the study of sound waves propagating through the Sun called?

The study of sound waves propagating through the Sun is called helioseismology.

The Sun is not solid, but its hot plasma vibrates in global and local oscillation modes. Convection near the surface continually drives and damps many of these waves. By measuring tiny changes in the Sun’s surface brightness and line-of-sight motion, researchers can infer conditions deep inside the star.

Solar oscillations were first detected in the early 1960s, with prominent variations having periods of about five minutes. By the mid-1970s, scientists understood that many oscillations travel through the Sun and can reveal its internal structure. The field’s name combines “helio,” meaning Sun, with “seismology,” the study of vibrations.

Helioseismology is related to asteroseismology, which studies oscillations in other stars, and geoseismology, which studies Earth’s interior. The terms are not interchangeable: “solar seismology” may be understandable informally, but helioseismology is the established scientific name. The technique has mapped the Sun’s internal rotation, measured sound-speed variations, and helped resolve the solar-neutrino problem.