VOLATILE DELIVERY TO PLANETS FROM WATER-RICH PLANETESIMALS AROUND LOW-MASS STARS

Abstract

Most models of volatile delivery to accreting terrestrial planets assume that\nthe carriers for water are similar in water content to the carbonaceous\nchondrites in our Solar System. Here we suggest that the water content of\nprimitive bodies in many planetary systems may actually be much higher, as\ncarbonaceous chondrites have lost some of their original water due to heating\nfrom short-lived radioisotopes that drove parent body alteration. Using N-body\nsimulations, we explore how planetary accretion would be different if bodies\nbeyond the water line contained a water mass fraction consistent with chemical\nequilibrium calculations, and more similar to comets, as opposed to the more\ntraditional water-depleted values. We apply this model to consider planet\nformation around stars of different masses and identify trends in the\nproperties of Habitable Zone planets and planetary system architecture which\ncould be tested by ongoing exoplanet census data collection. Comparison of such\ndata with the model predicted trends will serve to evaluate how well the N-body\nsimulations and the initial conditions used in studies of planetary accretion\ncan be used to understand this stage of planet formation.\n