Atmospheric retrievals of exoplanetary transmission spectra provide important constraints on various properties, such as chemical abundances, cloud/haze properties, and characteristic temperatures, at the day–night atmospheric terminator. To date, most spectra have been observed for giant exoplanets due to which retrievals typically assume hydrogen-rich atmospheres. However, recent observations of mini Neptunes/super-Earths, and the promise of upcoming facilities including the James Webb Space Telescope (JWST), call for a new generation of retrievals that can address a wide range of atmospheric compositions and related complexities. Here we report Aurora, a next-generation atmospheric retrieval framework that builds upon state-of-the-art architectures and incorporates the following key advancements: (a) a generalized compositional retrieval allowing for H-rich and H-poor atmospheres, (b) a generalized prescription for inhomogeneous clouds/hazes, (c) multiple Bayesian inference algorithms for high-dimensional retrievals, (d) modular considerations for refraction, forward scattering, and Mie scattering, and (e) noise modeling functionalities. We demonstrate Aurora on current and/or synthetic observations of the hot Jupiter HD 209458 b, mini Neptune K2-18b, and rocky exoplanet TRAPPIST-1 d. Using current HD 209458 b spectra, we demonstrate the robustness of our framework and cloud/haze prescription against assumptions of H-rich/H-poor atmospheres, improving on previous treatments. Using real and synthetic spectra of K2-18b, we demonstrate an agnostic approach to confidently constrain its bulk atmospheric composition and obtain precise abundance estimates. For TRAPPIST-1 d, 10 JWST-NIRSpec transits can enable identification of the main atmospheric component for cloud-free, CO₂-rich, and N₂-rich atmospheres and abundance constraints on trace gases, including initial indications of O₃ if present at enhanced levels (∼10–100 Earth levels).

系外行星透射光谱的大气反演对昼夜大气终结者的各种特性提供了重要的约束，例如化学丰度、云/雾特性和特征温度。迄今为止，大多数系外行星的光谱都被观测到，因此检索通常假设富含氢的大气层。然而，最近对迷你海王星/超级地球的观测，以及包括詹姆斯韦伯太空望远镜 (JWST) 在内的即将到来的设施的前景，需要新一代的检索来解决广泛的大气成分和相关的复杂性。在这里，我们报告了 Aurora，这是一种基于最先进架构的下一代大气检索框架，并结合了以下关键进步：(a) 允许富氢和贫氢大气的广义成分检索，(b) 非均匀云/雾的广义处方，(c) 用于高维检索的多种贝叶斯推理算法，(d) 对折射的模块化考虑、前向散射和 Mie 散射，以及 (e) 噪声建模功能。我们展示了对热木星 HD 209458 b、迷你海王星 K2-18b 和岩石系外行星 TRAPPIST-1 d 的当前和/或合成观测结果的极光。使用当前的 HD 209458 b 光谱，我们证明了我们的框架和云/雾霾处方相对于富氢/贫氢大气假设的稳健性，改进了以前的处理方法。使用 K2-18b 的真实和合成光谱，我们展示了一种不可知的方法来自信地限制其大气成分并获得精确的丰度估计。对于 TRAPPIST-1 d，10 个 JWST-NIRSpec 凌日可以识别无云 CO 的主要大气成分₂和 N ₂丰富的大气和对痕量气体的丰度限制，包括 O _{3 的}初始迹象，如果存在于增强水平（~10-100 地球水平）。