Top row: transmission spectrum of WASP-52b observed by ESPRESSO at the Na doublet, Hα, and K D₁ lines. Signatures arising from the center-to-limb variation and Rossiter–McLaughlin effects have been corrected. The gray line shows the unbinned transmission spectrum in grids of 0.01 Å. The black circles are binned into intervals of 0.1 Å (i.e., 10 × binned). The red lineshows the best-fit planet absorption model. The error bars show the propagated photon noise. Bottom row: best-fit residuals.