A high-resolution polarimetry map of the circumbinary disk around UY Aurigae

We have obtained J-band (1.2 mu m) polarimetry observations of the circumbi nary disk around UY Aurigae. These observations were made possible by the u se of the University of Hawaii 36 element adaptive optics instrument, Hokup a'a, at the 3.35 m CFHT. The deep (120 minute), high-resolution (0." 15) po larization images reveal a centrosymmetric polarization signature from the light scattered off the circumbinary dust disk which is similar to 10(6) ti mes fainter than the stars in the binary system. A comparison with a Mie sc attering model of the circumbinary disk in UY Aurigae suggests that the pol arization signature is dominated by the smallest grains in the disk (simila r to 0.03 mu m) and further supports the hypothesis that the resolved light seen in the optical and infrared originates from a large flattened disk of dust surrounding both stars.