Mass–radius relations for the planet. In black are data taken from panels (A) and (B) of Figure 3 in Batygin & Stevenson (2013), while in gray are the data taken from Table 4 of Fortney et al. (2007) for a giant planet with no core (crosses) and M_c = 10 M_⊕ (filled circles). The labels "J1e," "J3e," and "J10e" refer to the 1 M_⊕, 3 M_⊕, and 10 M_⊕ core-mass models, while the label "J3ei" denotes the irradiated 3 M_⊕ core-mass model.