Bayesian inference of upper thermospheric conditions for HD 189733 b and GJ 3470 b. (a) Comparison of the best-fit model spectra (blue shaded area) and of the measured He triplet line for HD 189733 b (red data points). (b) Residualof the fitted models for HD 189733 b. The dotted horizontal lines mark 3-σ. (c) Comparison of the best-fit model H⁰ density (shaded blue area) and of the estimated H⁰ density from Lyα measurements for HD 189733 b (red data points). For the models, the blue area corresponds to the region of the posteriors between the 16 and 84% quantiles. d–f are similar to a–c, but for GJ 3470 b.