Mid-ir imaging polarimetry and circumstellar magnetic fields

We have obtained diffraction-limited images of the mid-infrared emission and polarization patterns in a number of southern-sky objects. By mapping the polarization produced in absorption or emission by aligned aspherical dust grains, we have been able to trace the detailed spatial structure of magnetic fields in the warm circumstellar material of young molecular-outflow sources and HII regions, in the expanding dust shell of the mass-losing star Eta Carinae, and in the inner parsec of the Galactic Centre.