Measured and modeled squared visibilities for HD 80883 using a limb-darkened star surrounded by uniform circumstellar emission (left) or by a ring of dust at the sublimation radius (right). The different colors of the data points represent the different spectral channels (one color per channel). The solid blue line showsthe expected visibility for the stellar photosphere alone, and the dotted blue line the best fit for the star + disk model. Both disk models provide a reasonable fit to the measured visibilities, with .