Polarimetric Measurements of Protoplanetary Disks with ExPo


Polarimetry is a powerful tool for detecting and characterizing exoplanets and protoplanetary disks as light scattered from circumstellar material is linearly polarized. We present the first light results of ExPo (Extreme Polarimeter) [1], a sensitive imaging polarimeter developed at Utrecht University that works in the visible part of the spectrum. Our first light observations at the 4.2-meter William Herschel Telescope (WHT) show that ExPo can reach the high-contrast ratios that are necessary to observe protoplanetary disks. We present images of the protoplanetary disks around the Herbig Ae star AB Aurigae and the T Tauri star SU Aurigae. Our results show the power of polarimetry for future projects e.g. the ZIMPOL arm of SPHERE, and the EPOL part of EPICS.

American Institute of Physics Conference Series