Transmission spectrum of HAT-P-12b as derived from the homogeneous reanalysis of all data from the ground and from the HST with their associated error bars. For reference and comparison, we overplot the values obtained by M15 (black empty squares). The blue dashed lines show plus–minus two scale heights from the weighted average value of k (blue dotted line). In magenta we show the values of S16 together with the suggested atmospheric model (magenta solid line). The cyan solid overplotted line represents the cloud-free, solar-composition model of HAT-P-12bfrom Fortney et al. (2010) for comparison. The blue solid line is a linear regression of the weighted k values.