Polarimetric & Spectropolarimetric Properties of FGK Type Stars and Extrasolar Systems

The study of extra solar planets represents a new exciting frontier for modern astronomy. Most of the results on extrasolar systems are obtained with Doppler surveys. Here we suggest a different approach aimed to study the polarimetric properties of the residual interplanetary dust. Dust can produce observable effects such as infrared emission excess (Beckwith & Sargent 1996; Spangler et al. 2001) and partial polarization of the star light via scattering (Mauron & Dole 1998; Yudin 2000), like in β Pictoris (Voshchinnikov & Krügel 1999). Some polarization could also be produced by a giant planet in a close orbit around the star (Saeger et al. 2000), but the resulting effect is too weak to be responsible for the polarizations actually observed.