May 26, 2011 | 8
What does a supernova sound like? Hopefully we will never find out directly—getting within earshot of an exploding star is probably a bad idea.
But a pair of researchers has nonetheless devised a way to represent supernovae in an auditory way, and the result is a rather interesting piece of abstract music. University of Victoria graduate student Alex Parker and University of California, Santa Barbara, postdoctoral researcher Melissa Graham made the video below using telescope observations of nearly 250 type Ia supernovae. Those cataclysms occur when a small, dense star known as a white dwarf grows too massive, becomes unstable, and explodes in a thermonuclear blast.
As Parker notes on his Web page, he and Graham assigned each supernova a piano or upright bass note, depending on the kind of galaxy where the supernova went off—massive host galaxies get bass notes, whereas less massive galaxies get piano notes. Relatively nearby supernovae are louder; more distant supernovae are quieter. And the way the supernova brightens and fades over time determines its pitch. The video shows a time-lapse animation, based on real telescope data, during which two weeks of actual time pass by each second.
Type Ia supernovae are of special astronomical interest because they can be used as cosmic distance markers. In the 1990s, two teams used those supernovae to show that the universe is accelerating in its expansion thanks to an unknown entity now called dark energy. The supernovae depicted in the video above (the brightnesses of which are not to scale) were detected between 2003 and 2006 by the Supernova Legacy Survey at the Canada–France–Hawaii Telescope, a project that aims to better constrain dark energy by collecting a large sample of type Ia supernovae at varying distances.
Image of Tycho’s supernova remnant: X-ray: NASA/CXC/Rutgers/K.Eriksen et al.; Optical: DSS