Eccentricity vs. semimajor axis for all confirmed transiting planets between 6–20 Earth radii. Colored circles are planets with measured spin-orbit angles. Blue circles are defined as aligned with spin-orbit angles of less than 30 degrees, and red circles are defined as misaligned with spin-orbit angles greater than 30 degrees. The gray region illustrates planets that are likely undergoing high-eccentricity tidal migration. The upper and lower limits of the track are set by the Roche limit and the tidal circularization timescale (Dong et al. 2021). The dotted-dashed line presents the theoretical upper limit of eccentricities as a result of planet-planet scattering, assuming a planet with a mass of 0.5 M_Jup and a radius of 2 R_Jup, for illustrative purposes (Petrovich et al. 2014). The data were compiled from the NASA Exoplanet Archive as of October 30, 2024 (Christiansen et al. 2025). Stellar obliquity measurements were obtained from Knudstrup et al. (2024), in particular, Table B2, with recent updates.