Band-averaged visibilities as a function of baseline length. The dots with errorbars are the observations (blue dots: our VLTI data; red and green dots: IOTA and KI data taken from Monnier et al. 2005, 2006; and Eisner et al. 2009). The lines are best-fit geometric models (inclination , red: star-disk model; green: star-disk-halo model). Top panel: K band. Bottom panel: H band. Model parameters are listed in Table 3.