Sean Raymond
November 14, 2024
Zoom recording
Abstract:
Exoplanet systems come in a variety of shapes and sizes. Yet not all possible arrangements exist within the current sample. In this talk, I will first describe the current paradigm of planet formation and the resulting orbital architectures of planetary systems, including exoplanets and the Solar System. Then we will explore planetary systems that are dynamically stable but do not appear to form naturally (at least, with our current models). These include multi-resonant systems (reminiscent of Trappist-1, but with period ratios chosen to produce integer sequences of mathematical importance), as well as exotic configurations (such as many-planet co-orbital systems). There exists a zoo of planetary systems that are unusual but stable for billions of years, and that would even survive their host star’s post-main sequence evolution. The question becomes, what would a ‘non-natural’ system represent — a beacon indicating the presence of an advanced civilization, or some as-yet-unknown formation process?