The next generation of telescopes will yield a substantial increase in the availability of high-resolution spectroscopic data for thousands of exoplanets. The sheer volume of data and number of planets to be analyzed greatly motivate the development of new, fast and efficient methods for flagging interesting planets for reobservation and detailed analysis. We advocate the application of machine learning (ML) techniques for anomaly (novelty) detection to exoplanet transit spectra, with the goal of identifying planets with unusual chemical composition and even searching for unknown biosignatures. We successfully demonstrate the feasibility of two popular anomaly detection methods (Local Outlier Factor and One Class Support Vector Machine) on a large public database of synthetic spectra. We consider several test cases, each with different levels of instrumental noise. In each case, we use ROC curves to quantify and compare the performance of the two ML techniques.

下一代望远镜将提供大量高分辨率光谱数据，用于分析成千上万个系外行星。我们提倡将机器学习技术应用于异常检测，以识别具有不寻常化学组成甚至寻找未知生物特征的行星的恒星过境光谱。我们成功地证明了两种流行的异常检测方法（局部异常因子和单类支持向量机）在大型公开数据库的合成光谱上的可行性，并使用ROC曲线量化和比较了这两种机器学习技术的性能。

利用机器学习进行异常检测，在系外行星大气中寻找新颖的化学反应