Observations of exozodiacal disks
Meeting Room 2, CMS
The zodiacal cloud has long been suspected to have extrasolar analogs, exozodiacal, debris clouds that remained elusive until very recently. Over the last decade, the presence of exozodiacal dust in the habitable zone around nearby stars, has essentially been discussed as a potential noise source that may compromise the ability of future exo-Earth finding missions to reach their goals. Our pioneering detection of exozodiacal dust around Vega in 2006 by near-IR interferometry shows that exozodis are by themself very interesting astrophysical objects. During this talk, I will review the current observations of exozodiacal dust disks around nearby main sequence stars, and show that, as a rule of thumb, the detected exozodiacal dust disks differ from the zodiacal cloud. I will then discuss possible dynamical scenarios that may give rise to an abundant production of exozodiacal dust. I will show that a promising scenario involves the outward migration of a planet destabilizing a planetesimal belt similar to the Kuiper belt, and responsible for a cometary bombardment.