As the compact object spinned, it might have wobbled or precessed about its axis, like a child's top winding down. The twin beam would then trace out great circles like jets of water from a spinning lawn sprinkler. In fact, when Chris Burrows of the European Space Agency did a detailed inspection of the Hubble images, he located a dim object that could be the source of the beams at the predicted location--about one-third light-year from the center of the supernova explosion.

Investigators are waiting for the spreading shockwave to illuminate features that may confirm Burrows' theory and solve other mysteries of dying stars. The shockwave is a physical wallop that will allow scientists to test new theories about the interaction of shockwaves. "We are beginning to see the signature of the collision, the hammer hitting the bell. This event will allow us to validate ideas we have built up over the past ten years of observation," Kirshner adds.

If the theories about the rings are correct, the whole structure surrounding the dead star should be an envelope of low-density gas wherein the matter is too diffuse to be observed. "The ring will form a light bulb emitting visible light and x-rays that will shine through and illuminate the matter outside," says Richard McCray of the University of Colorado in Boulder. "The light from the crash will give us a chance to see this invisible matter for the first time, and then perhaps we can unravel the mystery of the outer rings."

Image: HUBBLE SPACE TELESCOPE STARDUST. Debris from the core of the shattered star is spreading outward at 2,000 miles a second. Astronomers believe this process seeds galaxies with heavy elements such as iron.

The recent Hubble images are already clarifying how heavy elements that form planets and living organisms spread through the universe. "All the chemical elements in the universe--and our world--are believed to have been created by exploding stars before the solar system was formed," Kirshner says. "We are all from outer space, but we didn't get here on space ships; we arrived an atom at a time from exploding stars."

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