Top panel: mass-radius diagram in the transition domain between brown dwarfs and stars. Isochrones for 10, 5, 1, and 0.1 Gyr are shown for comparison. Bottom panel: radius as a function of system’s age for objects from 15 to 100 Jupiter masses. BT-SETTL isochrones are shown for 0.02 to 0.09 M_⊙. Color symbols indicate the mass range: 15–25 M_Jup (green), 37−40 M_Jup (blue), 59−65 M_Jup (black), and 89−97 M_Jup (pink).