Abstract

Contributed Talk - Splinter PlanetFormation

Thursday, 18 September 2025, 14:35

Observability of planet-induced structures within the inner few AU of protoplanetary disks.

Lukas Hildebrandt, Anton Krieger, Hubert Klahr, Julia Kobus, Alexander Bensberg, Sebastian Wolf
Christian-Albrechts-Universität zu Kiel, Max-Planck-Institut für Astronomie

We investigate the feasibility of detecting planet-induced structures within the innermost few astronomical units of protoplanetary disks, down to their inner rims. This study is motivated by previous detections of a wide variety of large-scale substructures—such as rings, gaps, and spirals—spanning tens to hundreds of au. Our specific goal is to assess the potential of interferometric observations to resolve planet-induced features on au-scale within PPDs in nearby star-forming regions. To this end, we conducted 3D hydrodynamic simulations of embedded planetary companions, followed by 3D Monte Carlo radiative transfer modeling. Based on these models, we computed and analyzed interferometric observables, assuming observations with the Very Large Telescope Interferometer (VLTI) in the K, L, M, and N bands, corresponding to the GRAVITY and MATISSE instruments. The hydrodynamic simulations exhibit mass-dependent planet-induced density waves that create observable substructures, most notably for the considered case of a 300 Earth mass planet. These substructures share similarities with observed large-scale structures and feature a prominent accretion region around the embedded planet. The visibilities show a detectable variability for multi-epoch VLTI/GRAVITY and VLTI/MATISSE observations, caused by the orbital motion of the planet, that are distinguishable from other sources of variability due to their unique combination of timescale and amplitude. Additionally, the non-uniform change of the visibilities at different baselines can be used to identify asymmetric structures. Furthermore, we show that multi-wavelength observations provide an approach to identify the fainter substructures and the signal of the accretion region.