James Webb telescope detects moon-forming disk around young exoplanet CT Cha b

An artistic rendering of a dust and gas disk encircling the young exoplanet, CT Cha b. (Image: NASA/ESA/CSA/ STScI/Gabriele Cugno)

NASA’s James Webb Space Telescope (JWST) has captured direct observations of a potential moon-forming disc encircling the young, massive exoplanet CT Cha b. Situated 625 light-years away, this discovery marks one of the first detailed characterisations of a circumplanetary disc beyond our Solar System.

CT Cha b orbits a host star just 2 million years old, still accumulating material. The disc itself lies approximately 74 billion kilometres from its star, a vast region where conditions appear favourable for moon formation.

JWST's infrared detectors unveil the disc as carbon-rich, providing the vital details of its physical properties and chemical make-up. This information assists astronomers in comprehending the resources for forming moons within massive worlds.

Observation of CT Cha b's disc offers a distinct insight into the early phases of planetary and satellite systems. It offers a comparative perspective to our own Solar System’s infancy, over four billion years ago, and refines models of planetary growth and satellite creation.

By using advanced infrared spectroscopy, JWST measured the temperature, density, and chemical make-up of the circumplanetary disc. This method enables researchers to detect the locations where moons can condense out of nearby gas and dust.

This pioneering observation highlights JWST's capacity to investigate planetary formation mechanisms in unparalleled detail. This will provide new avenues to uncover the birth and evolution of planets and moons throughout the galaxy.