The Sun has lots of sound waves bouncing around inside it. The Sun also has natural frequencies at which it can ring. It’s a bit like having lots of bells, large and small, all ringing together.
By measuring the frequencies, wavelengths and amplitudes of solar sound waves, we can find out what is going on inside the Sun. The diagram shows all these terms in one!
- to vibrate at a special frequency!
The Sun also has natural frequencies at which it resonates. Of course, there isn't a giant finger to 'ping' the Sun, but the inside of the Sun is really noisy with lots of rumbling from the convection motion just below the surface. The sound waves bounce around inside the Sun, taking about two hours to travel from one side to the other. The frequencies are too low for our ears to hear. If we could hear them there would be lots of different natural frequencies and harmonics at the same time, not a 'pure' note.
The Sun is a giant ball of plasma, but the density and temperature are not the same everywhere. The speed at which sound waves travel depends on the temperature, so the sound speed varies inside the Sun. You can find out more about what is under the Sun’s surface from other pages in this section.