Starshade scaling relations

Abstract

The New Worlds Observer enables high-contrast imaging by placing a space telescope in the dark shadow cast by an apodized starshade. Depending on the science requirements, we consider starshades that provide a wide range of contrast (from ~10^-4 to more than 10^-15) over an octave of wavelength (from UV to Visible) at a variety of inner working angles (from a few milliarcseconds to several arcseconds). The starshade-telescope system is described by many parameters, including starshade diameter, telescope diameter, starshade-telescope separation, and wavelength range, that interact non-linearly. In this paper, we show how the different parameters contribute to the starshade's performance and discuss the selection process for different science requirements.