Different theories exist about how planet forms in the dust disk and how this formation relates to the formation of the star at the center. Size and composition of the disk and how densities are distributed along the disk are important to understand their formation. Polarimetry of resolved disks constain the nature of the scattering bodies and if observed in the infrared it provides and insight into the dust grain structure that gives information of the processes happening in the disk. Accurate measurements are possible using a four beam polarimeter.
Nebulaes are responsible for the structure of the disk and observations of symmetries in their structures gives information about how the circumstellar matter forms. The study of symmetries of unresolved stars is only possible using infrared polarimetry by investigating the fraction of polarized sources against the intrinsic luminosity of stars.
The intrinsic polarization level and orientation gives information about the distribution of grains insight the cloud. Then, its long term variation is a direct indicator of the evolution state of stars and planets.
In addition, these studies can be applied to the whole range of stellar objects from brown dwarfs to massive blue stars. The study of magnetic fields and oter mechanisms producing polarization will complement the classical H-R diagrams commonly used in the understanding of stellar population.
Galactic Magnetic Fields
Gamma Ray Outbursts
Star and Planet Formation