Patterns across the radius valley: stellar-property dependence of the small-exoplanet distribution from a multi-catalogue database

The radius valley separating super-Earths from sub-Neptunes is a key diagnostic of small-planet formation and atmospheric evolution, yet its dependence on host-star properties remains debated. We address this question with a cross-matched database integrating most of the known small exoplanets and their host stars, built by combining published archives with a wide set of complementary stellar measurements. The dataset is going to be released through an interactive web application that supports flexible queries, downloads, and diagnostic plots, and is designed to provide a reproducible reference frame for population-level studies.

Using this resource, we carry out a population-level clustering analysis of the super-Earth and sub-Neptune distributions with respect to available stellar and planetary parameters, discriminating potential distinct sub-populations characterized by different evolutive histories.

We discuss how this empirical picture constrains current photoevaporation and core-powered mass-loss scenarios, and how the database can serve as a benchmark for population studies of small exoplanets ahead of PLATO.