PUB - Publikationen an der Universität Bielefeld

We present high spatial resolution observations of the dusty core of thePlanetary Nebula with Wolf-Rayet central star CPD-568032. These observationswere taken with the mid-infrared interferometer VLTI/MIDI in imaging modeproviding a typical 300 mas resolution and in interferometric mode usingUT2-UT3 47m baseline providing a typical spatial resolution of 20 mas. Thevisible HST images exhibit a complex multilobal geometry dominated by faintlobes. The farthest structures are located at 7" from the star. The mid-IRenvironment of CPD-568032 is dominated by a compact source, barely resolved bya single UT telescope in a 8.7 micron filter. The infrared core is almost fullyresolved with the three 40-45m projected baselines ranging from -5 to 51 degreebut smooth oscillating fringes at low level have been detected in spectrallydispersed visibilities. This clear signal is interpreted in terms of a ringstructure which would define the bright inner rim of the equatorial disk.Geometric models allowed us to derive the main geometrical parameters of thedisk. For instance, a reasonably good fit is reached with an achromatic andelliptical truncated Gaussian with a radius of 97+/-11 AU, an inclination of28+/-7 degree and a PA for the major axis at 345+/-7 degree. Furthermore, weperformed some radiative transfer modeling aimed at further constraining thegeometry and mass content of the disk, by taking into account the MIDIdispersed visibilities, spectra, and the large aperture SED of the source.These models show that the disk is mostly optically thin in the N band andhighly flared.