Wave amplitude perturbations for p₄ caused by the sunspot. Left: map of observed amplitudes A (color scale). The white lines are 2D rays traced through a sunspot model, such that the wave speed is enhanced by 10% inside the circle and transitions smoothly to the background value (53.28 km s^-1) at the dashed circle. The wavefronts are given by the black lines. The thick black lines indicate the boundaries of the caustics where rays intersect and wavefronts fold. Right: observed amplitudes A as a function of y at fixed distances from the sunspot ranging from x = 50 to 200 Mm. Notice the amplitude enhancements around y ~  ± 60 Mm.