Innovative Imaging of Young Stars: First Light ExPo Observations


We have developed an innovative imaging polariemter, ExPo, that excels in the imaging of the circumstellar environments of young stars. The basic physics that ExPo exploits is that starlight reflected from a star’s circumstellar environment becomes linearly polarised, making it easily separable from unpolarised starlight. Our preliminary results, from the William Herschel Telescope in La Palma, show that ExPo has successfully detected several known protoplanetary disks out to a much larger distance and at a finer resolution than previously observed. ExPo has also made a significant number of new detections of protoplanetary disks and stellar outflows. We use innovative data analysis techniques, related to speckle interferometry, to detect the innermost parts of the disk to much closer than any other techniques operating at visible wavelengths. In this paper I present highlights of ExPo’s first light observations.

16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun