The characterization of exozodiacal light emission is both important for the understanding of planetary systems evolution and for the preparation of future space missions aiming to characterize low mass planets in the habitable zone of nearby main sequence stars. The Large Binocular Telescope Interferometer (LBTI) exozodi survey aims at providing a ten-fold improvement over current state of the art, measuring dust emission levels down to a typical accuracy of ~12 zodis per star, for a representative ensemble of ~30+ high priority targets. Such measurements promise to yield a final accuracy of about 2 zodis on the median exozodi level of the targets sample. Reaching a 1 σ measurement uncertainty of 12 zodis per star corresponds to measuring interferometric cancellation (“null”) levels, i.e visibilities at the few 100 ppm uncertainty level. We discuss here the challenges posed by making such high accuracy mid-infrared visibility measurements from the ground and present the methodology we developed for achieving current best levels of 500 ppm or so. We also discuss current limitations and plans for enhanced exozodi observations over the next few years at LBTI.

Date Published: 4 August 2016
PDF: 12 pages
Proc. SPIE 9907, Optical and Infrared Interferometry and Imaging V, 99070X (4 August 2016); doi: 10.1117/12.2231839

Published in SPIE Proceedings Vol. 9907:
Optical and Infrared Interferometry and Imaging V
Fabien Malbet; Michelle J. Creech-Eakman; Peter G. Tuthill, Editor(s)