  We present mid-IR spectro-interferometry of the Seyfert type 1 nucleus of NGC
3783. The dusty circumnuclear environment is spatially resolved and the
wavelength dependence of the compact emission is discussed. The observations
were carried out with the MIDI instrument at the Very Large Telescope
Interferometer in the N-band. Spectra and visibilities were derived with a
spectral resolution of 30 in the wavelength range from 8 to 13 micron. For the
interpretation we developed a simple dusty disk model with small and variable
covering factor. At baselines of 65 and 69 m, visibilities in the range of 0.4
to 0.7 were measured. The N-band spectra show a monotonic increase of the
measured flux with wavelength with no apparent silicate feature around 10
micron. We find that the mid-IR emission from the nucleus can be reproduced by
an extended dust disk or torus with a small covering factor of the radiating
dust clouds. Our mid-IR observations of NGC 3783 are consistent with a clumpy
circumnuclear dust environment. The interpretation in terms of a dusty torus
with low covering factor supports a clumpy version of the unified scheme for
AGN. The inferred sizes and luminosities are in good agreement with dust
reverberation sizes and bolometric luminosities from optical and X-ray
observations.
