Polarization studies of star-forming regions

Massive stars remain most of their lifetime deeply embedded in their parental molecular cloud and therefore heavily extinguished by the circumstellar material, with A(V)>> 10 mag. Based on selected ultracompact HII regions (UCHIIs), we demonstrate the importance of polarization maps as a diagnostic tool to search for hidden illuminating sources, spatially unresolved circumstellar disks, and other morphological features of this class of objects. We present high-resolution near-infrared polarization maps of the HII region S 106, and the UCHIIs C61.48+0.09 and G5.89-0.39. Furthermore, we present the results of a study aimed at determining the influence and structure of the magnetic field in the early phases of low-mass star formation using submillimeter polarization maps of Bok globules.