Webb Confirms Giant Exoplanet 29 Cygni b Formed by Disk Accretion, Not Fragmentation
JWST directly imaged 29 Cygni b, a ~15 Jupiter-mass exoplanet, and found it enriched in heavy elements with a disk-aligned orbit, supporting formation by rapid accretion in a protoplanetary disk rather than star-like fragmentation—placing it at the dividing line between planet and star formation.