  The core of the nebula surrounding Eta Carinae has been observed with the VLT
Adaptive Optics system NACO and with the interferometer VLTI/MIDI to constrain
spatially and spectrally the warm dusty environment and the central object. In
particular, narrow-band images at 3.74 and 4.05 micron reveal the butterfly
shaped dusty environment close to the central star with unprecedented spatial
resolution. A void whose radius corresponds to the expected sublimation radius
has been discovered around the central source. Fringes have been obtained in
the Mid-IR which reveal a correlated flux of about 100Jy situated 0.3"
south-east of the photocenter of the nebula at 8.7 micron, which corresponds
with the location of the star as seen in other wavelengths. This correlated
flux is partly attributed to the central object, and these observations provide
an upper limit for the SED of the central source from 2.2 to 13.5 micron.
Moreover, we have been able to spectrally disperse the signal from the nebula
itself at PA=318 degree, i.e. in the direction of the bipolar nebula 310
degree) within the MIDI field of view of 3". A large amount of corundum (Al2O3)
is discovered, peaking at 0.6-1.2" south-east from the star, whereas the dust
content of the Weigelt blobs is dominated b silicates. We discuss the
mechanisms of dust formation which are closely related to the geometry of this
Butterfly nebulae.
