Context : The putative tori surrounding the accretion disks of active galactic nuclei ( AGNs ) play a fundamental role in the unification scheme of AGNs .
Infrared long-baseline interferometry allows us to study the inner dust distribution in AGNs with unprecedented spatial resolution over a wide infrared wavelength range .

Aims : Near- and mid-infrared interferometry is used to investigate the milli-arcsecond-scale dust distribution in the type 1.5 Seyfert nucleus of NGC 3783 .

Methods : We observed NGC 3783 with the VLTI/AMBER instrument in the K -band and compared our observations with models .

Results : From the K -band observations , we derive a ring-fit torus radius of 0.74 \pm 0.23 mas or 0.16 \pm 0.05 pc .
We compare this size with infrared interferometric observations of other AGNs and UV/optical-infrared reverberation measurements .
For the interpretation of our observations , we simultaneously model our near- and mid-infrared visibilities and the SED with a temperature/density-gradient model including an additional inner hot 1400 K ring component .

Conclusions :