BEAST (Bayesian Extinction and Stellar Tool) fits the ultraviolet to near-infrared photometric SEDs of stars to extract stellar and dust extinction parameters. The stellar parameters are age (t), mass (M), metallicity (M), and distance (d). The dust extinction parameters are dust column (Av), average grain size (Rv), and mixing between type A and B extinction curves (fA).

measure_extinction measures extinction due to dust absorbing photons or scattering photons out of the line-of-sight. Extinction applies to the case for a star seen behind a foreground screen of dust. This package provides the tools to measure dust extinction curves using observations of two effectively identical stars, differing only in that one is seen through more dust than the other.

DIRTY (DustI Radiative Transfer, Yeah!) computes the radiative transfer and dust emission from arbitrary distributions of dust illuminated by arbitrary distributions of sources (usually stars). It uses Monte Carlo methods to solve the radiative transfer problem in full 3D including non-equilibrium and equilibrium thermal dust emission. As are other similar models, DUSTY is computationally intensive; as a result, it is written in C++.