Over the last 50 years helioseismology has tremendously increased our knowledge about the physical properties of the Sun. Precise measurements of the oscillations on the solar surface are carried out with worldwide networks of observing stations as well as dedicated space experiments. These seismic investigations of the Sun are the only possibility to derive information about the solar interior. Asteroseismology continues this success by investigating stellar interiors.

An overview of helioseismology is given here.

For more detailed reviews of this exciting field of research we suggest

Jørgen Christensen-Dalsgaard
“Lecture Notes on Stellar Oscillations”

Laurent Gizon and Aaron C. Birch,
“Local Helioseismology”,
Living Rev. Solar Phys. 2,  (2005),  6. URL (cited on 10.03.2015):

An overview of asteroseismology is given here.

European Helio- and Asteroseismology Network