Stellar coronagraphy with a redundant array of telescopes in space: The multiple mask coronagraph

We describe a coronagraphic technique that can be used with an array of telescopes in space. It generalizes the use of Lyot's Masks and Roddier & Roddier's Phase Masks (Roddier & Roddier 1997) to an array of telescopes without the densification of the pupil recently proposed by Labeyrie et al. (1999) and Guyon & Roddier (1999, 2000). The proposed method consists of using an ensemble of masks set on the principal diffraction peaks of the point spread function. The best efficiency is obtained for a redundant configuration of the apertures. A linear array configuration is proposed for solving the problems of chromatism associated with phase mask coronagraphy and permits image reconstruction via tomographic techniques. A numerical simulation is made for a one-dimensional array of telescopes.