Abundant hydrocarbons in the disk around a very-low-mass star

TL;DR

This study uses JWST mid-infrared spectroscopy to analyze the hydrocarbon-rich chemical composition of a disk around a very-low-mass star, revealing insights into planet formation environments.

Contribution

First detection of a carbon-rich, hydrocarbon-dominated disk around a very-low-mass star using JWST spectroscopy.

Findings

Identification of 13 carbon-bearing molecules including ethane and benzene

Large hydrocarbon column densities indicating deep disk probing

High C/O ratio suggesting radial material transport

Abstract

Very low-mass stars (those <0.3 solar masses) host orbiting terrestrial planets more frequently than other types of stars, but the compositions of those planets are largely unknown. We use mid-infrared spectroscopy with the James Webb Space Telescope to investigate the chemical composition of the planet-forming disk around ISO-ChaI 147, a 0.11 solar-mass star. The inner disk has a carbon-rich chemistry: we identify emission from 13 carbon-bearing molecules including ethane and benzene. We derive large column densities of hydrocarbons indicating that we probe deep into the disk. The high carbon to oxygen ratio we infer indicates radial transport of material within the disk, which we predict would affect the bulk composition of any planets forming in the disk.