CMFGEN normalized line equivalent width (EW) as a function of radius for our best-fit model and the reference one. Top and bottom panels: line-forming region as a function of radius for He I 2s-2p and Brγ, respectively. The red/blue dotted line corresponds the location of the η_A’s photosphere. The black-solid line indicates the spatial resolution limit of GRAVITY and the black-dashed line shows the projected position of η_B at apastron, according with the mean orbital solution presented by Teodoro et al. (2016).