1998A&A...329..131M

The morphology of the material surrounding Herbig Ae/Be stars is still a topic of debate. Distinct models with different geometry and optical thickness are found to be compatible with the observed IR excess. This indicates that it is not possible to resolve this question by only looking at the fluxes. Therefore, this paper compares three known Herbig Ae/Be stars with very similar energy distributions but with different photometric behaviour, showing different spectral line profiles and circumstellar extinction. These three Herbig Ae/Be stars are studied both photometrically and spectroscopically. It is found that the parameters from the Kurucz atmosphere model, fitting their spectral energy distributions, are very alike. Notwithstanding this similarity in spectral energy distribution, HD 142666 has several indications of CS material in the line of sight, while HD 139614 and HD 144432 do not show any of these indications. Therefore the inner dust shell of these stars is assumed to be not spherical, but rather flattened. The observed differences are then interpreted as a difference in CS disk inclination with respect to the observer. As a result, it is concluded that at least some of the Herbig Ae/Be stars are surrounded by disks and also that modeling energy distributions should be done while having other restraining observations in mind.