Connecting Stellar Abundance with Element Volatility & Rocky Planet Composition

Abstract

<p>The formation and main element composition of rocky planets can be simulated as equilibrium condensation of the most common species in a protoplanetary disk with parameterized abundance patterns. We have developed an open access python code to perform condensation simulations based on a Gibbs free energy minimisation including thermochemical and stellar abundance databases. Our main objective was to provide a code that is easy to use, adapt, and expand. With our code, we simulated condensation for a representative selection of F, G and K stars. We analysed the influence of stellar abundance patterns and specific element ratios on the equilibrium chemistry in the protoplanetary disk. I will present our results about the connection between stellar elemental abundance patterns, volatility of elements, and planet composition. We found significant variations in condensation temperatures and planetary bulk compositions even for the conservative parameter range of 0.1 < C/O < 0.8, challenging previous assumptions regarding the general consistency of disk chemistry in low to medium C-systems. Our simulations show that the combined differences in various element ratios and overall metallicity of the system have an intricate effect on the condensation behaviour of solid phases. We systematise these effects in an effort to enable cursory estimations of planetary compositions.</p>