---------------------

 Title: 

            Probing Sub-AU Radii of Young Circumstellar Disks: Observations with the Keck and Palomar Testbed Interferometers

 ---------------------

 

 ---------------------

 Authors:

          J.A. Eisner, Caltech

          L.A. Hillenbrand, Caltech

          B.F. Lane, MIT

          R.L. Akeson, Michelson Science Center

          R.J. White, Caltech

          A.I. Sargent, Caltech

 

 ---------------------

 

 ---------------------

 Abstract:

 

          The structure of young circumstellar disks, and in particular of the regions within 1 AU of the central star, has important implications for disk accretion and planet formation.  We have observed a sample of T Tauri and Herbig Ae/Be stars with the Keck and Palomar Testbed Interferometers, supplemented by echelle spectroscopy and optical through near-IR photometry With these data, we constrain the geometries and temperatures of inner circumstellar dust disks, and compare our measurements with the predictions of physical disk models.  Analyzing our measured inner disk properties with those expected for magnetospheric accretion models, we find evidence that gaseous disk material extends further in toward the star than dust.  Finally, we discuss implications for terrestrial planet formation and the migration of giant planets.

 

 ---------------------