Overview

• JWST delivered the first direct chemical and physical measurements of a circumplanetary disk encircling CT Cha b, located about 625 light-years away.
• Spectroscopy identified seven carbon-bearing molecules in the disk, including acetylene and benzene, indicating a carbon-rich inventory.
• The disk’s chemistry contrasts with the host star’s circumstellar disk, where water was found but no carbon, suggesting fast chemical differentiation.
• Webb’s MIRI medium-resolution spectrograph and high-contrast processing isolated the faint planet–disk signal from the nearby host star roughly 74 billion km away.
• No moons were detected, and following today’s publication in The Astrophysical Journal Letters, the team plans a Webb survey of similar systems over the next year.