DUAL IMAGING POLARIMETRY OBSERVATIONS OF CIRCUMSTELLAR MATTER IN TW HYDRAE: THE NACO VIEW

摘要

We present adaptive optics (AO) dual imaging po-larimetry observations of two stars in the TW Hy-drae association: TW Hya and TWA 11 (HR4796). These young stars (age～10Myr) are surrounded by circumstellar matter. We have checked the ability of NAOS-CONICA at the VLT, in combination with a Wollaston prism, to detect and resolve the disks around them. We have been able to image the innermost parts of these disks (down to 11 AU for TW Hya and 5 AU for HR 4796 and to derive polarization intensity profiles. We show that AO dual imaging po-larimetry is a suitable technique to detect and study circumstellar disks.