0 Assigned ID: 581 ----- Attempting Submission 1 (Fri Apr 07 15:40:22 GMT 2017) ----- Debris disks around stars are thought to evolve from gas-rich protoplanetary disks and eventually lead to the formation of exoplanet systems. Millimeter, sub-millimeter and far IR observations tell us much about the nature of solid and molecular constituents, but UV absorptions in the spectra of stars central to edge-on disks reveal the nature of atomic gas constituents that lie within such systems. The debris disks around the stars Beta Pictoris and 49 Ceti have already been studied in some detail. We propose to expand the sample by studying four more such targets that were observed with STIS in the highest resolution echelle modes, and this investigation will significantly expand our understanding of intrinsically different systems or ones with different angles of inclination with respect to our sightline. We plan to measure element abundances, which should lead to insights on the composition of the orbiting material. Also, we expect to learn more about the local physical conditions by evaluating the relative populations of atoms in metastable electronic states and fine-structure levels of the ground states. Planets and Planet Formation 0 Regular false true false SUPPORTED