Panel a), the VEGA squared visibilities plotted as a function of in order to allow a comparison between data of different phases (i.e. different θ_UD) and effective wavelengths. Five models are overplotted: (1) the UD pulsating disk without CSE from the SPIPS algorithm (blue solid line); (2) the SPIPS UD pulsating disk + the CSE from Eq. (1) (red dotted line); (3) the SPIPS UD pulsating disk + the CSE from Eq. (1) but two times brighter (dashed line); (4) the SPIPS UD pulsating disk + the CSE or Eq. (1) but two times fainter (dash-dotted line); (5) the SPIPS UD pulsating disk + a background contribution filling the field of view of the interferometer (magenta dotted line). The residual between the observations and models 1 to 4 are shown in panels b), c), d), and e), respectively. In panels d) and e) we show only the data corresponding to phases intervals φ = 0.0−0.8 and φ = 0.8−1.0, respectively.