JWST/NIRCam Coronagraphy of the Young Planet-hosting Debris Disk AU Microscopii

TL;DR

This study uses JWST/NIRCam coronagraphy to image the AU Microscopii debris disk at 3-5 μm, revealing disk properties and constraining the presence of massive exoplanets beyond 20 au with unprecedented sensitivity.

Contribution

First infrared images of AU Mic debris disk at 3-5 μm, demonstrating NIRCam's capabilities and providing new constraints on wide-orbit giant planets.

Findings

First images of AU Mic debris disk at these wavelengths.

No compelling planetary candidates found beyond 20 au.

Sensitive enough to detect planets as small as 0.1 Jupiter masses.

Abstract

High-contrast imaging of debris disk systems permits us to assess the composition and size distribution of circumstellar dust, to probe recent dynamical histories, and to directly detect and characterize embedded exoplanets. Observations of these systems in the infrared beyond 2--3 $\mu$m promise access to both extremely favorable planet contrasts and numerous scattered-light spectral features -- but have typically been inhibited by the brightness of the sky at these wavelengths. We present coronagraphy of the AU Microscopii (AU Mic) system using JWST's Near Infrared Camera (NIRCam) in two filters spanning 3--5 $\mu$m. These data provide the first images of the system's famous debris disk at these wavelengths and permit additional constraints on its properties and morphology. Conducting a deep search for companions in these data, we do not identify any compelling candidates. However, with sensitivity sufficient to recover planets as small as $\sim 0.1$ Jupiter masses beyond $\sim 2^{\prime\prime}$ ($\sim 20$ au) with $5\sigma$ confidence, these data place significant constraints on any massive companions that might still remain at large separations and provide additional context for the compact, multi-planet system orbiting very close-in. The observations presented here highlight NIRCam's unique capabilities for probing similar disks in this largely unexplored wavelength range, and provide the deepest direct imaging constraints on wide-orbit giant planets in this very well studied benchmark system.