Towards the development of a semiautomatic pipeline for investigating the viscosity parameter of disks of Be stars by the analysis of light curves

In "Viscous Decretion Disk" (VDD) model for circumstellar disks Be stars, material is dynamically ejected near the equator of the star and diffuses outwards by means of viscous forces. Following the alfa-fisk approach for the VDD, we show that dynamical disk models coupled with the radiative transfer code HDUST can be used for constraining fundamental disk parameters, such as the alfa viscosity parameter, the base density, the orientation angle i of the disk and the mass injection rate, only through the analysis of two-color light curves of Be stars that cover a few years and show "bump-like" magnitude excesses. The form of the bump depends on the dynamical state of the disk during the whole process of construction and dissipation. We show that the state of the disk can be extracted from two-color light curves by fitting theoretical curves, derived from a grid of dynamical models that we computed, to the observed light curves. The alfa viscosity parameter works as a time scaling parameter, and is also obtained in the process of fitting, for each Be star