2009/12/15 by Eric Cady, Ruslan Belikov, Cady, Eric +27 · 1 citation
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy and Astrophysical Research #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Stellar, planetary, and galactic studies #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.0912.2938
27 pages, 13 figures
arxiv created 2009/12/15 · openalex publication_date 2009/12/15 · arxiv updated 2010/01/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy (THEIA) is a mission concept study for a flagship-class telescope-occulter system to search for terrestrial planets and perform general astrophysics with a space-based 4m telescope. A number of design options were considered for the occulter and telescope optical systems; in this paper we discuss the design of occulters and coronagraphs for THEIA and examine their merits. We present two optimized occulters: a 25.6m-radius occulter with 19m petals that achieves 10-12 suppression from 250-1000nm with a 75mas inner working angle, and a 20.0m-radius occulter with 10m petals that achieves 10-12 suppression from 250-700nm with a 75mas inner working angle. For more widely separated planets (IWA > 108mas), this second occulter is designed to operate at a second closer distance where it provides 10-12 suppression from 700-1000nm. We have also explored occulter/coronagraph hybrid systems, and found that an AIC coronagraph that exploits the symmetry of the PSF at the occulter can improve performance; however, it requires very accurate tolerances on the occulter manufacturing of the telescope/occulter system as the AIC does not cancel asymmetric terms. Other coronagraphs proved infeasible, primarily due to the fact that the residual starlight from the occulter is not a plane wave, and so is poorly suppressed by the coronagraph.