The spin-orbit alignment of the Fomalhaut debris disk
Absil, Olivier[Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Invited seminar at the European Southern Observatory
[en] The measurement of the Rossiter-MacLaughlin effect in transiting planetary systems has revealed a significant population of hot giant planets orbiting outside the equatorial plane of their parent star. In an attempt to improve our understanding of these spin-orbit misalignements, and discriminate between various scenarios, we propose to determine whether debris disks are located within the equatorial plane of their star using infrared spectro-interferometry. To validate our approch, we have chosen the bright star Fomalhaut and measured the orientation of its rotationnally-distorted stellar photosphere using micro-arcsecond precision VLTI/AMBER spectro-astrometry within the Br-gamma line. The derived poition angle is in perfect agreement with the position angle of the cold debris disk imaged in the visible and sub-millimeter domains. We discuss the implications of this result on our understanding of the dust grain properties in the Fomalhaut disk, and how this study can be extended to other debris disk systems.