Planet-Host Stars Across the Galaxy in the 2040s

TL;DR

By the 2040s, understanding planetary system formation and evolution across the Galaxy will require a comprehensive, high-resolution spectroscopic survey of planet-host stars in diverse Galactic environments, beyond current capabilities.

Contribution

This paper advocates for a large-scale, homogeneous spectroscopic survey of planet-host stars across the Galaxy to enhance understanding of planetary system diversity and evolution.

Findings

Need for a broad, high-resolution spectroscopic survey.

Survey will include diverse Galactic environments.

Aims to improve understanding of planetary system formation.

Abstract

By the 2040s, the exoplanet field will have moved from the discovery of a few thousand planets to hundreds of thousands, thanks to Gaia DR5, TESS, PLATO, Roman, and their successors. At that stage, the key bottleneck will no longer be planet detection, but our ability to understand how planetary systems form, evolve, and diversify across different stellar and Galactic environments. To address this, we need a large-scale, high-resolution spectroscopic survey of planet-host stars, spanning a broad range of Galactic environments (thin and thick disks, bulge, halo, clusters, associations), and including a well-defined control sample of non-hosts. Such a survey must deliver homogeneous stellar parameters, detailed abundance determinations, ages, and kinematics for tens of thousands of hosts, extending to the faint magnitudes probed by future missions but are beyond the reach of existing and currently planned spectroscopic facilities.