Hiding Dust Around $\epsilon$ Eridani

Abstract

With a Jupiter-like exoplanet and a debris disk with both asteroid and Kuiper belt analogs, $\epsilon$ 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 $\delta$ Eridani. While we were unable to detect the debris disk, we place stringent constraints on the scattered light surface brightness of $\sim 4\mu Jy/arcse{c}^2$. 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 $\epsilon$ 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 $>2\mu m$. 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.

References in corpus (13)

• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Probing for Exoplanets Hiding in Dusty Debris Disks: Disk Imaging, Characterization, and Exploration with HST/STIS Multi-Roll Coronagraphy
• CASSIS: The Cornell Atlas of Spitzer/Infrared Spectrograph Sources. II. High-resolution observations
• Spitzer/IRAC Limits to Planetary Companions of Fomalhaut and epsilon Eridani
• The Northern Arc of $\epsilon$ Eridani's Debris Ring as Seen by ALMA
• The effect of dust composition and shape on radiation-pressure forces and blowout sizes of particles in debris disks
• On the Morphology and Chemical Composition of the HR 4796A Debris Disk
• New HST data and modeling reveal a massive planetesimal collision around Fomalhaut
• Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multi-epoch Vortex Coronagraphy Upper Limits
• Multiband GPI Imaging of the HR 4796A Debris Disk
• What Sets the Radial Locations of Warm Debris Disks?
• MAMBO image of the debris disk around epsilon Eridani : robustness of the azimuthal structure
• Relating grain size distributions in circumstellar discs to the spectral index at millimetre wavelengths

Cited by in corpus (1)

• Spatially resolved imaging of the inner Fomalhaut disk using JWST/MIRI