Observational spectro-photometric data of R Lep, compared with the synthetic spectrum of the best-fitting time-step (violet). Photometry is plotted in green circles, while IRAS (Olnon et al. 1986) and NASA/IRTF (Rayner et al. 2009) spectra are plotted as black lines to allow qualitative verification of the photometric fit. The spectrum of the DARWIN models, for which the synthetic photometry fits best the corresponding observational data, is shown in violet.