Wheel of Stars

You are watching, and listening to, a musical clock made of stars.

To make this, I downloaded public data from Hipparcos, a satellite launched by the European Space Agency in 1989 that accurately measured over a hundred thousand stars. The data contains position, parallax, magnitude, and color information, among other things.

I used this information to plot the brightest stars, and cause them to revolve about Polaris (the North Star) very slowly, as the stars appear to do. Like the night sky, this is a sidereal time clock — it takes nearly 24 hours for the stars to fully rotate. You'll notice some familiar constellations, such as the Big Dipper, in there. As the stars cross zero and 180 degrees, indicated by the center line, the clock plays an individual note, or chime, for each star. The pitch of the chime is based on the star's B–V measurement (which roughly corresponds to color or temperature). The volume is based on the star's magnitude, or apparent brightness, and the stereo panning is based on the position on the screen (use headphones to hear it better).

Basically, this is a very literal kind of “music of the spheres,” and is typical of my projects, which often involve circles and music. This idea for making a music box out of stars was a natural progression from some previous projects of mine, like the Whitney Music Box and Musical Chess, which you might also enjoy.

Jim Bumgardner, October 3rd 2009

Featured on BoingBoing, Discover Magazine's Bad Astronomy blog, and Universe Today. Listen to a 10-minute MP3 excerpt of the sequence, or a 5-minute excerpt crossing the Pleiades, made with a different synthesis system that also uses parallax to give some of the stars a doppler effect.

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