Assess existence of an additional transiting planet (candidate ‘i’) in TRAPPIST-1

Determine whether an additional transiting exoplanet beyond the known TRAPPIST-1 planets is present—specifically the candidate ‘i’ suggested by a low-amplitude transit-like feature—and, if present, measure its orbital period and radius using JWST/MIRI and complementary observations.

Background

Independent analyses explored a possible low-amplitude transit-like structure consistent with a very small additional planet (candidate ‘i’). However, across different reductions and statistical treatments, the evidence remains below robust detection thresholds.

The TJB analysis, which included Gaussian process modeling of red noise, specifically reports no clear evidence supporting inclusion of a new transiting exoplanet in the fitted model, leaving the candidate’s existence unresolved.