Correlations between the Carbon-to-Oxygen Ratio and the Orbital and Physical Properties of Exoplanets

Abstract

Studies suggest that protoplanetary disks around stars with high carbon-to-oxygen (C/O) ratios can produce terrestrial planets with carbon-dominated compositions instead of silicon-dominated ones. While previous work studied the evolution of these disks and the planets that form within them, none analyze in detail how the differences in the surface density profiles of these disks could affect the architectures and iron and siderophile contents of exoplanetary systems. Here, we present a new study that uses the N-body integrator REBOUND and data from a sequential dust condensation model to simulate the formation of planets in systems with varying C/O ratios. We find that bulk density could be used to distinguish between silicon-rich and carbon-rich planets, though it may not be a reliable metric on its own.