Structure and evolution of circumplanetary disks (gas and solids)

Characterize the structure, thermodynamics, and time evolution of gas and solid components in circumplanetary disks across the relevant spatial scales, informed by observational constraints from circumplanetary disk detections and potential exomoon signatures.

Background

Circumplanetary disks may form during late stages of giant planet growth and govern satellite formation and gas accretion onto planets. The paper reviews initial detections (e.g., PDS 70c) and theoretical requirements (cooling timescales, flow morphology), highlighting the need for a comprehensive physical picture integrating multi-scale processes.

References

Open questions and problems that I would like to see resolved include, in no particular order: What is the structure and evolution of gas and solids in circumplanetary disks? This is a physics-rich problem with a wide range of relevant spatial scales. Informative constraints from circumplanetary disk, and possibly exomoon observations, will be needed to inform theoretical work.

— Planet formation theory: an overview  (2412.11064 - Armitage, 2024) in Section “Some open questions”, Item 6

Whether this process can produce a substantial planetary obliquity depends on the relative angular momenta of the planet and CPD and on their coupling and evolutionary timescales. Our simulations do not include the planetary spin, so their applicability to the obliquities of Saturn or Uranus remains speculative. We defer a quantitative investigation of CPD--planet spin coupling to future work.

— Magnetically Driven Obliquity in Circumplanetary Disks and Twisted Bipolar-jet Formation  (2609.10035 - Chametla et al., 9 Sep 2026) in Section 6, “Conclusions”