Astronomers like to say we are the byproducts of stars, stellar furnaces that long ago fused hydrogen and helium into the elements needed for life through the process of stellar nucleosynthesis. But what about the heavier elements in the periodic chart, elements such as gold, platinum and uranium? Astronomers believe most of these "r-process elements" -- elements much heavier than iron -- were created, either in the aftermath of the collapse of massive stars and the associated supernova explosions, or in the merging of binary neutron star systems.