Ninesimulated transit light curves generated by PRISM, showing the smallest detected starspot for 3 trends, T_eff: top row; λ_obs: middle row; P: bottom row. Top row: simulations of a 1.5 R_⊕ super-Earth planet transiting a 3200 K, 0.155 R_⊙ M4V dwarf star with i = 90.0°, P = 1 d, λ_obs = 600 nm, and rms scatter 150 ± 7.5 ppm. Each column on the top row shows a different T_spot, where T_spot = 3000, 3050, and 3100 K (left to right). The smallest detected r_spot are r_spot = 0.026R_* (red), r_spot = 0.035R_* (blue), and r_spot = 0.044R_* (green). Middle row: simulations of a 3.0 R_⊕ Neptune-sized planet transiting a 4100 K, 0.623 R_⊙ K5V dwarf star with i = 90.0°, P = 4 d, T_spot = 3900 K, and rms scatter 200 ± 10 ppm. Each column on the middle row shows a different λ_obs, where λ_obs = 600, 785, and 1000 nm (left to right). The smallest detected r_spot values are r_spot = 0.052R_* (red), r_spot = 0.061R_* (blue), and r_spot = 0.079R_* (green). Bottom row: simulations of a 2.25 R_⊕ sub-Neptune planet transiting a 3700 K, 0.493 R_⊙ M1V dwarf star with i = 90.0°, T_spot = 3550 K, λ_obs = 1000 nm and rms scatter 100 ± 5 ppm. Each column on the bottom row shows a different P, where P = 2 d, 3 d and 4 d (left to right). The smallest detected r_spot are r_spot = 0.044R_* (red), r_spot = 0.044R_* (blue), and r_spot = 0.052R_* (green). The solid lines represent the noise-free synthetic light curves containing the starspot anomaly, while the filled circles represent the spot-free synthetic light curves (see Sect. 3) with added Gaussian noise.