Prospects for detecting decreasing exoplanet frequency with main sequence age using PLATO

TL;DR

This paper explores PLATO's potential to detect a decline in exoplanet frequency with stellar age, focusing on systems with multiple planets and planetary scattering effects over time.

Contribution

It introduces a method to assess PLATO's ability to observe decreasing exoplanet frequency due to dynamical instability in multi-planet systems.

Findings

PLATO may detect decreasing planet frequency for super-Earth mass planets.

Two-planet systems show potential for trend detection based on instability timescales.

Initial system compactness influences the likelihood of observable frequency trends.

Abstract

The space mission PLATO will usher in a new era of exoplanetary science by expanding our current inventory of transiting systems and constraining host star ages, which are currently highly uncertain. This capability might allow PLATO to detect changes in planetary system architecture with time, particularly because planetary scattering due to Lagrange instability may be triggered long after the system was formed. Here, we utilize previously published instability timescale prescriptions to determine PLATO's capability to detect a trend of decreasing planet frequency with age for systems with equal-mass planets. For two-planet systems, our results demonstrate that PLATO may detect a trend for planet masses which are at least as massive as super-Earths. For systems with three or more planets, we link their initial compactness to potentially detectable frequency trends in order to aid future investigations when these populations will be better characterized.