Mass-radius relations for accreting Pop III stars. Dashed lines show the relations followed by protostars accreting at different rates, and the solid blue line is the relation followed by main sequence stars. The filled circles show the mass and radius for each particle at the beginning of our simulations. The stellar radii for the black circles were obtained with the accretion rates provided by ENZO, whereas the stellar radii for the red circles were obtained assuming ṁ = 0.0 M_⊙/yr.