The sound of variable stars
Stars can change in brightness over time for many different reasons (for example, see the long list of variable star designations of the American Association of Variable Star Observers). Herein, the ‘timbre’ of such variations is transformed into sound, incorporating elements from astronomy (such as variable star light curves), mathematics (utilising Fourier series), physics (involving waves, gravitation, and stellar physics), and music (highlighting the potential of the new timbre, as shown in Recordings).
This concept was initially presented through sound samples demonstrating various types of stellar variability at the biennial outreach event ‘La nuit de la science’ in Geneva, Switzerland, on 6-7 July, 2024:
(both versions work correctly in Chrome and Safari browsers only).
Below, you can listen to the audio files extracted from the outreach presentation linked above. Please note that:
- the timbre derives from the harmonic content present in the light curve (i.e., from the shape of a wave),
- the loudness is influenced by the amplitude, fundamental frequencies, and harmonics,
- the pitch indicates a characteristic (rescaled) frequency of a specific type of variability in comparison to others.
A soundfont was generated using a subset of 11 types of variable stars, omitting the ones that exhibited distinct multi-frequency tones, such as RR Lyrae stars in double pulsation mode and multi-periodic δ Scuti stars, and the combination of variability types seen in Cepheids within eclipsing binary stars.
Published: July 12, 2024 | Last Updated: November 7, 2024 | Resources licensed under CC BY 4.0 
