2016/01/11 by Mamadou N’Diaye, Mamadou N'Diaye, Rémi Soummer +4
Engineering · Physics and Astronomy · #Adaptive optics and wavefront sensing #Aperture (computer memory) #Apodization #Coronagraph #Exoplanet #Optical Polarization and Ellipsometry #Planet #Spitzer Space Telescope #Stars #Stellar, planetary, and galactic studies #Telescope #Wavefront #astro-ph.EP #astro-ph.IM
paper · pdf · doi:10.3847/0004-637x/818/2/163
9 pages, 6 figures, ApJ accepted on 01/04/2016
arxiv created 2016/01/11 · openalex publication_date 2016/02/17 · arxiv updated 2016/03/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
ABSTRACT We introduce a new class of solutions for Apodized Pupil Lyot Coronagraphs (APLC) with segmented aperture telescopes to remove broadband diffracted light from a star with a contrast level of 10 10 . These new coronagraphs provide a key advance to enabling direct imaging and spectroscopy of Earth twins with future large space missions. Building on shaped pupil (SP) apodization optimizations, our approach enables two-dimensional optimizations of the system to address any aperture features such as central obstruction, support structures, or segment gaps. We illustrate the technique with a design that could reach a 10 10 contrast level at 34 mas for a 12 m segmented telescope over a 10% bandpass centered at a wavelength of 500 nm. These designs can be optimized specifically for the presence of a resolved star and, in our example, for stellar angular size up to 1.1 mas. This would allow one to probe the vicinity of Sun-like stars located beyond 4.4 pc, therefore, fully retiring this concern. If the fraction of stars with Earth-like planets is , with 18% throughput, assuming a perfect, stable wavefront and considering photon noise only, 12.5 exo-Earth candidates could be detected around nearby stars with this design and a 12 m space telescope during a five-year mission with two years dedicated to exo-Earth detection (one total year of exposure time and another year of overheads). Our new hybrid APLC/SP solutions represent the first numerical solution of a coronagraph based on existing mask technologies and compatible with segmented apertures, and that can provide contrast compatible with detecting and studying Earth-like planets around nearby stars. They represent an important step forward toward enabling these science goals with future large space missions.