Imaging of the Vega Debris System using JWST/MIRI

TL;DR

This study presents JWST/MIRI mid-infrared images of the Vega debris disk, revealing a symmetric, broad Kuiper-belt-like ring and inner warm debris, providing insights into potential planetary influences and disk structure.

Contribution

First high-resolution mid-infrared imaging of Vega's debris disk with JWST, revealing detailed disk morphology and constraints on potential planetary bodies.

Findings

Detected a symmetric debris disk with a broad Kuiper-belt-like ring at 80-170 au.

Identified a warm inner debris region with a gap at 60 au, suggesting planetary influence.

Constrained the mass of potential shepherding planets to less than 6 Earth masses.

Abstract

We present images of the Vega planetary debris disk obtained at 15.5, 23, and 25.5 microns with the Mid-Infrared Instrument (MIRI) on JWST. The debris system is remarkably symmetric and smooth, and centered accurately on the star. There is a broad Kuiper-belt-analog ring at 80 to 170 au that coincides with the planetesimal belt detected with ALMA at 1.34 mm. The interior of the broad belt is filled with warm debris that shines most efficiently at mid-infrared along with a shallow flux dip/gap at 60 au from the star. These qualitative characteristics argue against any Saturn-mass planets orbiting the star outside of about 10 au assuming the unseen planet would be embedded in the very broad planetesimal disk from a few to hundred au. We find that the distribution of dust detected interior to the broad outer belt is consistent with grains being dragged inward by the Poynting-Robertson effect. Tighter constraints can be derived for planets in specific locations, for example any planet shepherding the inner edge of the outer belt is likely to be less than 6 Earth masses. The disk surface brightness profile along with the available infrared photometry suggest a disk inner edge near 3-5 au, disconnected from the sub-au region that gives rise to the hot near-infrared excess. The gap between the hot, sub-au zone and the inner edge of the warm debris might be shepherded by a modest mass, Neptune-size planet.