Are there aligned grains around young stellar objects?

The light at visible and near-infrared wavelengths from Young Stellar Objects (YSOs) is polarized by scattering by small particles, mostly dust grains. In the denser circumstellar disks there is multiple scattering which is responsible for the observed patterns of aligned polarization vectors. Circular polarization has also been detected in a few YSOs, both integrated over the whole re-ion or spatially resolved. We investigate the interpretation of these observations in the context of models incorporating scattering by grains of ellipsoidal shape. The Fredholm integral equation method and the T-matrix method are used to obtain the elements of the scattering matrix and yield very similar results. We consider the effects of grain rotation and investigate the F-11 and F-41 elements which have particular relevance to circular polarization. The results are finally used to compute polarization maps for comparison with observations.