Transit of HD 189733 b observed by TESS with a cadence of 120 s. Black dots represent the mean of consecutive subsets of ten observations. Maximum likelihood fits from the n_DR = 1 and n_DR = 0 models are marked with orange and blue lines respectively, one sigma uncertainties are marked as shaded areas. The residuals of the highest likelihood n_DR = 1 and n_DR = 0 model fits are shown in the middle and the bottom of the figure, respectively. The feature between t − t_c ≈ −2200 s and t − t_c ≈ −300 s is an eclipse of a dark region with a radius of $r_{\min }=9.8_{-2.2}^{+4.5}$ ° and a contrast of 0.04.