With a Jupiter-like exoplanet and a debris disk with both asteroid and Kuiper belt analogs, $ε$ Eridani has a fascinating resemblance to our expectations for a young Solar System. We present a deep HST/STIS coronographic dataset using eight orbit visits and the PSF calibrator $δ$ Eridani. While we were unable to detect the debris disk, we place stringent constraints on the scattered light surface brightness of $\sim 4 \, μJy/arcsec^{2}$. We combine this scattered light detection limit with a reanalysis of archival near and mid-infrared observations and a dynamical model of the full planetary system to refine our model of the $ε$ Eridani debris disk components. Radiative transfer modeling suggests an asteroid belt analog inside of 3 au, an intermediate disk component in the 6 - 37 au region and a Kuiper belt analog co-located with the narrow belt observed in the millimeter (69 au). Modeling also suggests a large minimum grain size requiring either very porous grains or a suppression of small grain production, and a radially stratified particle size distribution. The inner disk regions require a steep power law slope ($s^{-3.8}$ where $s$ is the grain size) weighted towards smaller grains and the outer disk prefers a shallower slope ($s^{-3.4}$) with a minimum particle size of $> 2 \, μm$. These conclusions will be enhanced by upcoming coronographic observations of the system with the James Webb Space Telescope, which will pinpoint the radial location of the dust belts and further diagnose the dust particle properties.
Direct Imaging for the Debris Disk around $ε$ Eridani with the Cool-Planet Imaging Coronagraph
CAS Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院行星科学重点实验室，紫金山天文台）；School of Astronomy and Space Science, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）；CAS Center for Excellence in Comparative Planetology（中国科学院比较行星学卓越创新中心）
Azimuthal brightness modulation reveals hidden rings in CI Tau
Università degli Studi di Milano（米兰大学）；Max-Planck Institute for Astronomy (MPIA)（马克斯·普朗克天文学研究所）；Queen Mary University of London（伦敦大学玛丽女王学院）；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，IPAG）；University of Cambridge（剑桥大学）；University of Leeds（利兹大学）
