Mean magnetic field strength on the dynamo surface (B^dyn_mean) vs. the planetary radius in panel (a) and a similar figure for the magnetic field strength on the planetary surface at the rotational pole (B^polar_dipole) in panel (b). The symbol area scales as a function of the incident stellar heat flux (in ﹩\mathrm{erg}\,{{\rm{s}}}^{-1}\,{\mathrm{cm}}^{-2}﹩) with the smallest and largest symbol representing 2 × 10⁸ and 10¹⁰, respectively. The color of the symbols represents the mass of the planets.