Michael Sitko
Department of Physics
University of Cincinnati

Formation and Evolution of Solar Systems: Extrasolar Mineralogy

Recent ground-based and space-based (i.e. Hubble Telescope) images of nearby (<150 parsecs) stars have uncovered numerous cases of stars with debris disks similar to that which our own sun must have possessed in its youth. In the case of the sun, this debris provided the raw material from which the terrestrial planets and the cores of the jovian planets formed. Spectroscopic studies of the debris disks surrounding these stars reveal a wealth of information about the material from which planets in these systems may be forming, or have already formed. By comparing the spectroscopic signatures of these systems with materials in the laboratory, it is possible to ascertain the mineralogical composition and degree of crystallinity of the disk material. One goal of these studies is to understand the physical and chemical processing of this material as a function of system age, structure, and presence of stellar and sub-stellar companions. Many of these systems, as well as our own solar system, seem to require large-scale circulation of the material between 1-6 million years of age, but (for the moment) the details of that process remain cloudy at best.