Johan Mazoyer (JPL)

Title --- High-contrast imaging of exoplanets with future large ground- and space-based telescopes : current limitations and perspectives

Abstract --- The long term goal of direct imaging is the detection and spectral characterization of Earth-like planets around nearby Sun-like stars, to identify signposts of biological markers. Two concept space-missions, LUVOIR and HabEx are currently studied to achieve this goal and will be proposed for the decadal survey in 2020. However, numerous instrumental challenges have still to be overcome. In particular, the current generation of ground- and space-based telescope instruments use coronagraphs optimized for circular, often un-obstructed apertures. However, to achieve the necessary performance to detect obtain images and spectra of Earth-sized planets, we have to address the problem of diffractions created by more complex apertures, with discontinuities, due to the central obscuration of the secondary, the spiders, or the segmentation of the primary. In this talk I will present recent high contrast methods to correct for these complex apertures. Finally I will present some of the current remaining challenges for future high-contrast missions.