A New Concept for Direct Imaging and Spectral Characterization of Exoplanets in Multi-planet Systems

Abstract

We present a novel method for direct detection and characterization of exoplanets from space. This method uses four collecting telescopes, combined with phase chopping and a spectrometer, with observations on only a few baselines rather than on a continuously rotated baseline. Focusing on the contiguous wavelength spectra of typical exoplanets, the (u, v) plane can be simultaneously and uniformly filled by recording the spectrally resolved signal. This concept allows us to perfectly remove speckles from reconstructed images. For a target comprising a star and multiple planets, observations on three baselines are sufficient to extract the position and spectrum of each planet. Our simulations show that this new method allows us to detect an analog Earth around a Sun-like star at 10 pc and to acquire its spectrum over the wavelength range from 8 to 19 μm with a high spectral resolution of 100. This method allows us to fully characterize an analog Earth and to similarly characterize each planet in multi-planet systems.