University of Minnesota astronomers led an international team of researchers who have developed a new three-dimensional visualization of the famous Cassiopeia A supernova remnant that gives astrophysicists new clues about how exploding stars form new stars and solar systems. The findings were presented nationally for the first time this week during the American Astronomical Society meeting in Long Beach, Calif.

"By tracing backward from this new 3-D picture, we hope to find clues to the structure of the star as it exploded," said University of Minnesota astronomy professor Lawrence Rudnick, the lead researcher for the NASA Spitzer Space Telescope observation program that yielded data for the 3-D visualization.

Tracey DeLaney, a 2004 Ph.D. graduate of the University of Minnesota and postdoctoral researcher at the Massachusetts Institute of Technology, created the first three-dimensional fly-through of a supernova remnant based on data from NASA's Chandra X-ray Observatory, NASA's Spitzer Space Telescope and ground-based optical telescopes.

"We have always wanted to know how the pieces we see in two dimensions fit together with each other in real life," DeLaney said. "Now we can see for ourselves with this `hologram' of supernova debris."

Also released this week was a movie of Cassiopeia A's changes over the past eight years, based on data from NASA's Chandra X-ray Observatory and produced by Daniel Patnaude of the Smithsonian Astrophysical Observatory and his colleagues. Some of the University of Minnesota's data from Chandra were also used in creating the time-lapse images.

Together, the 3-D simulation and time-lapse movie will help astrophysicists understand how supernovas seed interstellar gas with heavy elements, heat it with the energy of their radiation, and trigger blast waves that help new stars form. University of Minnesota astronomy graduate student Karl Isensee also helped to identify which chemical elements emerged from the exploded star.

These ground-breaking research findings of Cassiopeia A were made possible through a collaboration with the Astronomical Medicine project based at Harvard University. The goal of the project is to bring together the best visualization techniques from two very different fields-astronomy and medical imaging.