ExoEarth Candidate Yield from a Future Direct Imaging Mission
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Introduction {#intro}
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The number of habitable extrasolar Earth-like planets (exoEarths) detected and spectroscopically characterized is a key scientific metric for future missions that aim to find habitable conditions on exoplanets and possibly signs of life. The predicted exoEarth yield will inform telescope design and mission lifetime, and may ultimately help select high-contrast imaging technologies. Radial velocity measurements and results from the *Kepler* Mission have constrained the fraction of M dwarfs that harbor roughly Earth-sized planets in their habitable zones (exoEarth candidates), $\eta_{\Earth} \sim 0.4$ , although the uncertainties of these estimates are large and the planet radius/mass and orbital period range used to define $\eta_{\Earth}$ vary within the literature. For Sun-like stars $\eta_{\earth}$ is even less certain, with estimates ranging from $\sim$ 0.05 – 0.2 [@2013PNAS..11019273P; @2014arXiv1404.2960M; @Silburt:2014aa]. For such low values of $\eta_{\earth}$ the expected total number of candidate exoEarths observed within the mission lifetime (exoEarth candidate yield) could be low, making yield maximization extremely important.

Many previous studies have estimated the exoEarth candidate yield for future exoplanet imaging missions. @2004ApJ...607.1003B introduced the concept of obscurational completeness to quantify the impact of a non-zero inner working angle (IWA) 