2004ApJ...602..978S

We present an improved model for the circumstellar environment of the peculiar star HD 62623 taking into account the gas around the central star and the dust present in the outer parts of the envelope. We compare our results with photometric observations and near-infrared interferometric observations obtained with aperture masking interferometry performed at the Keck I telescope from the literature. This modeling has two goals: to provide a framework for understanding the partially resolved object shown by the visibility curves, and to allow investigation of the envelope of HD 62623 by discrimination between proposed models. We show that a better fit for both the photometric and interferometric data is obtained by adding the gas in the inner part of the envelope. The present model allows us to confirm a smaller value for the inner dust radius, i.e., R_in=15-20 R_*. The dust temperature we obtain at this boundary is T_in=1500 K. Our simulation seems to indicate that, even with a nearly spherical model, a sufficient density (ρ∼10^–18 g/cm3) to form dust at the inner radius is obtained. Despite our multiple tentatives, we were not able to reproduce the visibility curve at 1.65 µm showing an unresolved object. At 1.24, 2.26, and 2.08 µm, the agreement between our best model and the visibility data is not good enough to draw a very strong conclusion, but it may indicate that the circumstellar environment of HD 62623 is based on different grain sizes and optically thick dust.