Impact of the choice of limb darkening on the light curve fit and measured transit depth for the case of no limb darkening and photometric scatter of σ = 1000 ppm. Top left: median stellar intensity profile I _s(μ)/I ₀ (blue line) from the transit fit to the simulated observations using the [u ₁, u ₂] limb-darkening parameterization. The 1σ and 2σ confidence intervals are shown by the shaded regions. Bottom left: median transit model (blue) obtained from the transit fit with the [u ₁, u ₂] limb-darkening parameterization. The 1σ and 2σ confidence intervals are shown by the shaded regions. Top middle: same as top left considering the [r ₁, r ₂] parameterization. Bottom middle: same as bottom left considering the [r ₁, r ₂] parameterization. Right: Probability density distributions of the measured transit depth minus the true transit depth for the [u ₁, u ₂] (blue) and [r ₁, r ₂] (red) parametrizations. The transit depths measured using [u ₁, u ₂] and [r ₁, r ₂] are centered on the expected value, but the posterior distribution obtained with [r ₁, r ₂] is wider.