Subset of super-Earths of interest (with a better chance at being hydrogenated), displayed by their density and equilibrium temperature T_eq. The size indicates the planet radius. Top plot: color indicates the planet Emission Spectroscopy Metric (ESM; Kempton et al. 2018); planets with the highest T_eq are the best candidates for magma oceans planets. Bottom plot: color indicates the hydrogenation index χ (see Sect. 6.2); all colored planets are good candidates for hydrogenated planets (χ > 1), the others are not colored. Source: NASA Exoplanet Archive¹.