Architecture of exoplanetary systems

We apply our framework on observed and synthetic multi-planetary systems presenting their mass, radius, density, core mass, and core water mass fraction architectures; and explore the relationships between a system's (mass) architecture and other properties. Our simulations suggest that: (a) Similar architectures are the most common outcome of planet formation, (b) internal structure and composition of planets shows a strong link with their system architecture, (c) most systems inherit their mass architecture from their core mass architecture, (d) most planets which started inside the ice line and formed in-situ are found in systems with Similar architecture, and (e) most Anti-Ordered systems should be rich of wet planets, while most observed mass Ordered systems should have many dry planets.

We find that, in good agreement with theory, observations are biased towards discovering systems whose density architectures are Similar, Mixed, or Anti-Ordered. This study engenders novel questions and new parameter spaces for understanding theory and observations. Future studies may utilise our framework to not only constraining our knowledge of an individual planet, but also the multi-faceted architecture of an entire planetary system.

We also speculate on the role of system architectures in hosting habitable worlds.