Overview

• JWST's MIRI medium-resolution spectrograph detected seven carbon-bearing molecules in the circumplanetary disk, including acetylene, benzene, diacetylene, propyne, ethane, hydrogen cyanide, and carbon dioxide.
• The planet–disk system lies roughly 46 billion miles (about 74 billion km) from the young host star, establishing that the material is distinct from the star’s accretion disk.
• Researchers isolated the planet’s faint signal from stellar glare using high-contrast methods, enabling the first direct chemical and physical measurements of a circumplanetary disk.
• The study, led by Gabriele Cugno and Sierra L. Grant and published in The Astrophysical Journal Letters, probes material accreting onto the massive companion CT Cha b about 625 light-years away.
• No moons are seen in the Webb data, and the team plans a follow-up Webb survey over the next year to assess the diversity of circumplanetary disks and their chemistries.