JWST Exoplanet Candidate
JWST spots a candidate fifth planet inside HR 8799
A faint source just above three sigma sits where a dynamically stable inner giant could orbit, but confirmation is still required.
Briefed September 11, 2026 · Aliens in the Clouds
Developing Preprint · Candidate Not Confirmed
Jayke Nguyen and 22 colleagues report a candidate planet directly imaged with JWST's NIRISS aperture-masking interferometer. The source appears at a contrast of about two times ten to the minus four in the 3.8-micron filter, at a projected separation near 150 milliarcseconds. Their models translate that into a planet of a few to several Jupiter masses orbiting roughly seven astronomical units from HR 8799.
The candidate lies just above the study's three-sigma contrast curve. Its separation is compatible with Gaia and Hipparcos proper-motion constraints if it is bound, and its position is near a stable solution in a 3:1 orbital resonance with known planet e. That agreement is encouraging rather than conclusive: another epoch must show common motion and recover the source. Confirmation would make HR 8799 the first directly imaged system known with five planets.
Why it matters
The result tests both a new high-contrast JWST pipeline and the architecture of the best-known directly imaged multiplanet system. A repeat detection could reveal how widely separated giant planets organize themselves.
What the source establishes
Verified new preprint and reported just-over-three-sigma source. Candidate planet only; it has not yet been confirmed as bound, and no life or artificial technology is claimed.
Published by Aliens in the Clouds. These AI-assisted summaries link to their sources and distinguish reported claims from established findings. Skinny Ed is a fictional mascot; High Thoughts are comedy. Send a correction with its source.