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B[e] stars are hot stars surrounded by circumstellar gas and dust responsiblefor the presence of emission lines and IR-excess in their spectra. How dust canbe formed in this highly illuminated and diluted environment remains an openissue. HD 62623 is one of the very few A-type supergiants showing the B[e]phenomenon. We obtained nine calibrated visibility measurements using theVLTI/MIDI instrument in SCI-PHOT mode and PRISM spectral dispersion mode withprojected baselines ranging from 13 to 71 m and with various position angles.We used geometrical models and physical modeling with a radiative transfer codeto analyze these data. The dusty circumstellar environment of HD 62623 ispartially resolved by the VLTI/MIDI even with the shortest baselines. Theenvironment is flattened and can be separated into two components: a compactone whose extension grows from 17 mas at 8 microns to 30 mas at 9.6 microns andstays almost constant up to 13 microns, and a more extended one that isover-resolved even with the shortest baselines. Using the radiative transfercode MC3D, we managed to model HD 62623's circumstellar environment as a dustydisk with an inner radius of 3.85+-0.6 AU, an inclination angle of 60+-10 deg,and a mass of 2x10^-7Mo. It is the first time that the dusty disk inner rim ofa supergiant star exhibiting the B[e] phenomenon is significantly constrained.The inner gaseous envelope likely contributes up to 20% to the total N bandflux and acts like a reprocessing disk. Finally, the hypothesis of a stellarwind deceleration by the companion's gravitational effects remains the mostprobable case since the bi-stability mechanism does not seem to be efficientfor this star.

Resolving the dusty circumstellar environment of the A[e] supergiant HD 62623 with the VLTI/MIDI