Normalised flux versus wavelength in angstroms. The observed spectra of α Cen B (black dots) is overlaid with SAPP’s best-fit model from the spectroscopy module (magenta solid line). This contains HARPS, UVES, and HR10 spectra with original resolving powers R ∼ 118 000, 47 000, and 20 000 respectively. The UVES and HARPS spectra have been convolved down to the resolution of HR10.