Planets larger than Neptune have elevated eccentricities.

ABSTRACT: NASA's Kepler mission identified over 4,000 extrasolar planets that transit (cross in front of) their host stars. This sample has revealed detailed features in the demographics of planet sizes and orbital spacings. However, knowledge of their orbital shapes-a key tracer of planetary formation and evolution-remains far more limited. We present measurements of eccentricities for 1,646 Kepler planets, 92% of which are smaller than Neptune. For all planet sizes, the eccentricity distribution peaks at e = 0 and falls monotonically toward zero at e = 1. As planet size increases, mean population eccentricity rises from ⟨e⟩ = 0.05 ± 0.01 for small planets to ⟨e⟩ = 0.20 ± 0.03 for planets larger than ∼3.5 Earth-radii R_⊕. The overall planet occurrence ra

SUBMITTER: Gilbert GJ 

PROVIDER: S-EPMC11929400 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature