White light-curve fits for the HST WFC3 G102 (left) and G141 (right) data of LTT 9779 b. In each case, the top plot shows the raw light curve (top panel), corrected light curve and best-fit model (second panel), the residuals having removed the best-fit model (third panel), and the AC function (bottom panel). The lower graphic is a corner plot for the fit. As with the majority of HST data sets, there is a correlation between the white light-curve depth and the parameters for the systematics (Equation (1)), thereby indicating that achieving absolute transit depths is difficult with these data. For the data studied here, the G141 data show the highest correlation. Nevertheless, no major offset in the transit depth was found between the two visits.