We lay out the capabilities and limitations of starshade-based missions aiming to measure the reflected light spectra of temperate planets from an imaging perspective. We use the Starshade Imaging Simulation Toolkit for Exoplanet Reconnaissance to conduct high fidelity end-to-end optical simulations, taking a step forward from simplified analytical equations, exploring and quantifying the impact of an array of observational conditions, including natural parameters such as target star types, planet types, distances, planet phases, and exo-zodiacal dust, and starshade perturbations such as tilt, shift off line of sight, edge errors, and glint. We find that signal-to-noise ratio (SNR) requirements used for establishing detection and spectral characterization, is not suitable under realistic observation conditions for a wide range of targets. We show that even if we assume that the spatially distributed, time-varying background noise could be known and calibrated to a level of 1%, each target star will need its own SNR requirement based on its unique observation conditions, nearly always resulting in a higher threshold SNR, with values as high as X5 from currently established requirement, and in some cases impossible to detect. We conduct statistical analysis using end-to-end optical simulations, taking into account observationally based priors and update previously established completeness values for an array of target stars and mission configurations, accounting for starshade perturbations, and background knowledge at a level of one percent and find that completeness values are negatively impacted and reduced by up to 50% across targets even at ranges shorter than 10 pc. Finally, we utilize information from over hundreds of thousands of detailed imaging simulations to map accessible target stars for both optimistic and pessimistic scenarios, reassessing the expected capabilities of starshade-based high contrast direct imaging missions.

中文翻译：

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系外行星成像性能包络用于基于星影的任务

我们列出了基于恒星任务的能力和局限性，这些任务旨在从成像角度测量温带行星的反射光谱。我们使用用于系外行星侦察的Starshade成像仿真工具包进行高保真的端到端光学仿真，从简化的分析方程式向前迈进了一步，探索并量化了一系列观测条件的影响，包括目标星等自然参数类型，行星类型，距离，行星相位和黄道带尘埃以及恒星阴影扰动（例如倾斜，视线偏移，边缘误差和闪烁）。我们发现，用于建立检测和频谱表征的信噪比（SNR）要求在大范围目标的实际观察条件下并不适用。我们证明，即使我们假设可以知道空间分布的，随时间变化的背景噪声并将其校准到1％的水平，每个目标恒星也将根据其独特的观测条件而需要自己的SNR要求，几乎总是会导致较高的SNR阈值，其值比当前确定的要求高出X5，在某些情况下无法检测到。我们使用端到端光学模拟进行统计分析，同时考虑到基于观测的先验，并针对一系列目标恒星和任务配置更新先前建立的完整性值，将星云扰动和背景知识解释为百分之一和发现即使在小于10 pc的范围内，完整度值也会受到负面影响，并且整个目标最多可降低50％。最后，