Sounding the Sun through a technique similar to seismology has opened a new era for understanding the Sun's interior. The COROT satellite has now applied this technique to three stars, directly probing the interiors of stars beyond the Sun for the first time.

When global oscillations of the Sun were discovered, scientists realized they had opened a window to the Sun's interior. Similar in the way the propagation of seismic waves on Earth provides information concerning our planet's interior, sound waves travel throughout the Sun and collect and carry information about what is happening below the Sun's surface. These oscillations can also be observed at other stars. They can be detected through the variation in the light emitted by the star as the surface wobbles, the technique used by COROT. This reveals the internal structure of the star, and the way energy is transported from the core to the surface. The three stars probed by COROT —- known as HD49933, HD181420, and HD181906 — are similar to the Sun. They are rather far away, so their brightness doesn't blind COROT's sensitive instruments. The image is courtesy of the European Space Agency (ESA).