The viscous disk properties of 80 Be stars

We investigated the properties of $80$ Be star disks, using the time dependent viscous decretion disk (VDD) model to interpret their mid-infrared continuum fluxes. Besides estimating the typical parameter ranges for such disks, this approach allowed us to relate the disk structure to its evolutionary status. In this contribution, we present a brief summary of the recently published results, and discuss some properties and time-scales of the VDD model solution.