Music of the stars

Forget dendrochronology, there’s a new compound -ology in town: astroseismology.

The new Kepler telescope is designed to measure tiny fluctuations in stars’ brightness. Stars are giant balls of gas, which is continually in motion, and the massive movement of gas creates great pressure waves, effectively sound waves of very low frequency. As these sound waves resonate within a star, they slightly change both the brightness and the colour of the star’s light. Kepler can detect these changes, and by working backwards, scientists can deduce information about the sound waves and the star.

Like a musical instrument, bigger stars create sound waves at lower pitches. And there are also harmonics in the signal, which indicate the depth of origin of the sound waves, and the amount of hydrogen or helium they passed through. The sounds are thousands of times lower than we can hear. They can of course be speeded up, but it doesn’t sound any more like “Twinkle twinkle”.

This is a repost from my Mucknell Abbey blog.

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