Abstract:
The polarization of the light that we observe and that is generated in very different astrophysical scenarios encodes rich information about the physical mechanisms taking place in those regions. Spectro-polarimetric measurements can be used to choose between competing AGN models. Moreover, maser radiation coming from stellar envelopes, the light passing through the interstellar dust and also the cosmic microwave background are polarized. I will show the advantages of using polarimetric techniques to study the physical conditions of all these different scenarios but I will focus on solar and stellar physics where these techniques are widely applied and developed.