Extracted spectra in photoelectrons for WASP-33 (continuous thick lines) and BD+36 488 (continuous thin lines) for the R1000B and R500R grisms (green and red colors, respectively). Vertical dashed black lines indicate the atmospheric and stellar lines used to align the spectra. The yellow shaded region highlights the wavelength coverage of the data sets used to construct the white light curves (see Sect. 3.1).