Birth cluster simulations of planetary systems with multiple super-Earths: initial conditions for white dwarf pollution drivers

TL;DR

This study uses stellar cluster simulations to explore the initial orbital configurations of super-Earth systems, revealing that a significant fraction develop eccentricities conducive to white dwarf pollution, providing valuable initial conditions for future research.

Contribution

It introduces detailed cluster simulations of multi-planet super-Earth systems, highlighting their potential to produce eccentricities that influence white dwarf pollution, and supplies initial conditions for further studies.

Findings

Approximately 30% of planets attain eccentricities ≥ 0.1 by cluster dissolution.

Simulations include 8,000 stars with a Kroupa initial mass function.

Results inform initial conditions for subsequent planetary evolution models.

Abstract

Previous investigations have revealed that eccentric super-Earths represent a class of planets which are particularly effective at transporting minor bodies towards white dwarfs and subsequently polluting their atmospheres with observable chemical signatures. However, the lack of discoveries of these planets beyond a few astronomical units from their host stars prompts a better understanding of their orbital architectures from their nascent birth cluster. Here, we perform stellar cluster simulations of 3-planet and 7-planet systems containing super-Earths on initially circular, coplanar orbits. We adopt the typical stellar masses of main-sequence progenitors of white dwarfs ($1.5\,\mathrm{M}_{\odot}$-$2.5\,\mathrm{M}_{\odot}$) as host stars and include 8,000 main-sequence stars following a Kroupa initial mass function in our clusters. Our results reveal that about 30 per cent of the simulated planets generate eccentricities of at least 0.1 by the time of cluster dissolution, which would aid white dwarf pollution. We provide our output parameters to the community for potential use as initial conditions for subsequent evolution simulations.