Bridging stellar evolution and planet formation: from birth, to survivors of the fittest, to the second generation of planets

TL;DR

This White Paper addresses how dust processing in circumstellar environments across stellar birth, evolution, and death regulates when, where, and how planets form and survive. It advocates bridging stellar evolution and planet formation by focusing on dust kinematics and macrostructure to connect small-scale dust physics with large-scale planet–host interactions. It outlines 2030s advancements that will improve sensitivity and resolution, and a 2040s goal of ultra-high-angular-resolution infrared interferometry to image inner discs and dusty envelopes across the Hertzsprung–Russell diagram, enabling comprehensive tests of current theories. The work highlights the potential to constrain snowline dynamics, migration, and second-generation planet formation, with broad implications for exoplanet demographics and Solar System history.

Abstract

Stars and planets form, live, and evolve in unison. Throughout the life of a star, dusty circumstellar discs and stellar outflows influence the further evolution of both the star(s) and their orbiting planet(s). Planet-forming discs, winds of red giant branch (RGB) or asymptotic giant branch (AGB) stars, and post-RGB/post-AGB discs are examples of such host environments where dust physics plays a key role. The physical processes that occur during each of these stages establishes how the Solar System as well as exoplanetary systems were formed, are evolving, and will eventually die. This White Paper aims to bridge the fields of stellar evolution and planet formation by peering into the dust kinematics and macrostructure formation, and its effect on planet-host interaction, in dusty environments from stellar birth to death. Near-future advancements in the 2030s will enable the detection, orbital monitoring and atmospheric/mineralogical characterisation of close-in (proto)planets across diverse stages of stellar evolution. To take full advantage of these developments by the 2040s, we should develop the capabilities required to image the varied dusty environments in which planets are entrained over their lifetime. This will enable extensive testing of current theoretical understandings - from the micro-scales of dust assembly to the deeply interlinked macro-scales of planet-host interactions - across diverse settings often too small, distant, and faint to be resolved in the next decade, simultaneously providing valuable constraints on the two-way interplay of dusty host environments and planetary formation/evolution.