Optimal Occulter Design for Finding Extrasolar Planets

Abstract

One proposed method for finding terrestrial planets around nearby stars is to use two spacecraft--a telescope and a specially shaped occulter that is specifically designed to prevent all but a tiny fraction of the starlight from diffracting into the telescope. As the cost and observing cadence for such a mission will be driven largely by the separation between the two spacecraft, it is critically important to design an occulter that can meet the observing goals while flying as close to the telescope as possible. In this paper, we explore this tradeoff between separation and occulter diameter. More specifically, we present a method for designing the shape of the outer edge of an occulter that is as small as possible and gives a shadow that is deep enough and large enough for a 4m telescope to survey the habitable zones of many stars for Earth-like planets. In particular, we show that in order for a 4m telescope to detect in broadband visible light a planet 0.06 arcseconds from a star shining $10^{10}$ times brighter than the planet requires a specially-shaped occulter 50m in diameter positioned about $72,000$ km in front of the telescope.

14 pages, 4 figures, 15 subfigures

References in corpus (6)

• Phase-Induced Amplitude Apodization of Telescope Pupils for Extrasolar Terrestrial Planet Imaging
• A Coronagraph with a Band-Limited Mask for Finding Terrestrial Planets
• Circularly Symmetric Apodization via Starshaped Masks
• Spiderweb Masks for High-Contrast Imaging
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• The Big Occulting Steerable Satellite (BOSS)

Cited by in corpus (14)

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• The search for habitable worlds: 1. The viability of a starshade mission
• The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Interim Report
• Analyzing the designs of planet finding missions
• Analytic Modeling of Starshades
• Boundary diffraction wave integrals for diffraction modeling of external occulters
• Optical Verification Experiments of Sub-scale Starshades
• Externally Occulted Terrestrial Planet Finder Coronagraph: Simulations and Sensitivities
• Interstellar communication. II. Application to the solar gravitational lens
• Fourth-order Coronagraph for High-Contrast Imaging of Exoplanets with Off-axis Segmented Telescopes
• Implementing non-scalar diffraction in Fourier optics via the Braunbek method
• Optimization of starshades: focal plane versus pupil plane
• Direct High-Resolution Imaging of Earth-Like Exoplanets
• Occulter to Earth: Prospects for studying Earth-like planets with the E-ELT and a space-based occulter