From April, 2003 until August, 2006, the Canada-France-Hawaii Telescope watched four parts of the sky as often as possible. Armed with the largest digital camera in the known universe, CFHT monitored these four fields for a special type of supernova (called Type Ia supernovae) which are created by the thermonuclear detonation of one or more white-dwarf stars. These explosions are extremely energetic, and can be seen across vast distances in space.
These four fields covered roughly 16 times the area of the full Moon on the sky, or roughly 1/10,000 of the entire sky. Even though such a small fraction of the sky was monitored, 241 Type Ia supernovae were seen during the period of observation.
This video is a compilation of the 241 Type Ia supernovae seen in these fields during the CFHT Legacy Survey. The four Deep Fields are shown in color, and the positions of all the supernova are illustrated as time progresses. The animation is rendered at 15 frames per second, and each frame corresponds to just under a single day (one second in the animation corresponds to roughly two weeks of real time).
Each supernova is assigned a note to be played:
Volume = Distance: The volume of the note is determined by the distance to the supernova, with more distant supernova being quieter and fainter.
Pitch = "Stretch:" The pitch of the note was determined by the supernova's "stretch," a property of how the supernova brightens and fades. Higher stretch values played higher notes. The pitches were drawn from a Phrygian dominant scale.
Instrument = Mass of Host Galaxy: The instrument the note was played on was determined by the properties of the galaxy which hosted each supernova. Supernovae hosted by massive galaxies are played with a stand-up bass, while supernovae hosted by less massive galaxies are played with a grand piano.
Note that the brightness of the supernovae as shown in the animation are not to scale. Because they are so distant, even these extremely powerful explosions appear very faint upon reaching us here on Earth.