Mass–radius diagram. The gray circles show the exoplanet data from exoplanets.eu and the red stars show the Solar System planets. The black point corresponds to the measured value for TOI- 3568 b. Internal structure models for planets with pure rock and pure ice (H2O) compositions from Zeng et al. (2019) are depicted by the solid red and orange lines, respectively. Additionally, evolutionary models for H/He-dominated planets from Fortney et al. (2007) are shown for a pure H/He without a core (green line), and for a core of 10 M_⊕ (blue line) and 25 M_⊕ (purple line) of heavier elements. Iso-density curves are also represented by the black lines.