Conny Aerts

Because the earthquakes create waves, they travel into the planet, they bounce back at the iron core, and seismographs detect it, and then we can do all sorts of fun physics and chemistry of our planet.

And we do the same, but then for stars.

Yeah, so that's a bit different because the starquakes are happening all the time because it's a gas.

And so you have motions, right?

Up and down motions, but also more complex motions.

And if you press a gas and then release it, it creates sound waves.

That's a bit like music in a theater hall.

So for me, stars are three-dimensional musical objects.

holes, concert holes, right?

And so the nice thing is that starquakes are always there.

Luckily for us humans, the earthquakes die out quickly, right?

Yeah, that's correct, because anybody in nature vibrates.

And so, yeah, stars do that all the time and they do it permanently, which for us astrophysicists is great because we can measure the up and down motion.

Why?

Because it gives changes in the temperature of the star.

And so the brightness of the star changes as a function of time.

And then we have our seismographs that measure these changes as a function of time.

Yeah, that's correct.

But yeah, like we cannot hear these sound waves with our ears.

So we see the brightness variations because the sound is only propagating there where there is gas.