TESS phase-folded light curve around the Lagrangian points L₅ (top panel) and L₄ (middle panel) of LHS 1140 c (see Sect. 5.2). The expected location of the transit is marked by vertical dashed lines. The median transit model inferred from the analysis of the L₄ dimming is shown as a solid red line (middle panel) and a dashed line in the upper panel to guide the eye on the photometric scatter of the L₅ region. The 1σ confidence interval is shown in the middle panel as a shaded red region. Bottom panel: residuals of the model for the L₄ region. All panels show bin data points corresponding to 6.6 min (light blue, ten data points inside the transit duration) and 13.2 min (black, five data points inside the transit duration).