Density of known exoplanets versus their equilibrium temperatures. These data come from the online DACE database maintained by Observatory of Geneva (https://dace.unige.ch/) and are taken from the catalog of Otegi et al. (2020), which is an exoplanet catalog based on reliable, robust, and - to the greatest possible extent – accurate mass and radius measurements of transiting planets up to 120 earth masses (Otegi et al. 2020). Top: density vs. equilibrium temperature for all planets. Bottom: same as above but limited to planets with radii of smaller than 3 Earth radii. The dotted line shows a simple least-square fit to the data.