2001ApJ...561L.131H

Physical models of circumstellar disks surrounding pre-main-sequence stars are currently constrained primarily by the spectral energy distribution of the system. Here we present first results from a survey of nearby Herbig Ae stars using nulling interferometry. We measure the spatial extent of the mid-IR emission for the stars HD 150193, HD 163296, and HD 179218. The results indicate that the size of mid-IR emission around Herbig Ae stars may be much smaller than current models predict. The observations constrain ∼90% of the 10 µm flux to be within an approximately 20 AU diameter region, providing significant spatial limits for disk models. These results demonstrate the scientific potential for nulling interferometry to study circumstellar disks with better spatial discernment than is possible with standard mid-IR imaging.