Upper panel: phase coverage of the thermal emission observations. Middle panel: airmass as a function of orbital phase for each observation. Lower panel: S/N_spec in the spectral order of the He infrared triplet (10 830 Å) as a function of orbital phase for each observation. The colours represent different observation dates. The dashed and dotted lines indicate the eclipse duration (T₁₄) and the fully in-eclipse duration (T₂₃), respectively.