[en] High levels of warm dust observed in the inner regions of planetary systems are known as exozodis, reflecting their similarities with the Solar System's zodiacal cloud. Whilst the population of cold, outer debris discs is well characterised observationally and understood theoretically, many mysteries remain regarding the observations of exozodiacal dust. The observed small dust grains have a short lifetime against collisions and radiative forces. Even if they were resupplied from the collisional grinding of a population of larger parent bodies, as commonly suggested to explain cold, outer debris discs, the parent bodies could not sustain the observed dust levels in steady-state for anywhere near the age of the system. Further theoretical investigations, alongside observations of the population of exozodis, are required in order better understand the origin of the exozodiacal dust. Interferometry is perfectly suited to better characterising this population, as the emission from the exozodi can be readily disentangled from the stellar emission. We present results of a statistical survey that aims to characterise the population of exozodis around nearby stars using CHARA/FLUOR and VLTI/PIONIER, alongside theoretical investigations into the manner in which the observed exozodiacal dust may be linked with the dynamical evolution of the planetary system.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Bonsor, A.
Augereau, J. C.
Absil, Olivier ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)