Broadband transmission spectrum of HD 189733b. Left: linear fit (dashed black line) to the measured planet-to-star radius ratio as a function of the logarithmic wavelength. The red bands represent the 1–3 σ confidence levels. Right: comparison of our results with Pont et al. (2013) in blue and Cristo et al. (2022) in green. Shifts were applied to the literature results to match, approximately, the radius level of 550 nm.