M–R diagram with the synthetic planets used in the study (black dots). The black, blue, and light blue bars correspond to uncertainties of 5, 10, and 20% in mass and 3, 5, and 10% in radius, respectively. The crosses represent observed planets from the revisited catalog in Otegi et al. (2020). The synthetic planets are plotted against the composition lines of pure-iron (brown), Earth-like (light brown), and water ice (blue).