Stellar intensity profiles from the PHOENIX (solid purple line) and ATLAS (solid black line) stellar grids for the HST WFC3.IR.G141 filter as a function of μ (, where z is the normalised distance from the centre of the stellar disc). We overlaid the best fit limb darkening models for the power-2 (dotted red), quadratic (dotted cyan), and non-linear (dotted green) laws. We also plotted the range of the parameter space allowed by the limb darkening models using the derived parameter uncertainties after multiplying the intrinsic theoretical model uncertainties provided by LDTk by 40× for the quadratic model and 10× for the power-2 model. The intrinsic uncertainties of the modelled grids were not changed for the derivation of the non-linear LD parameters.