标题： MOA-2022-BLG-091Lb 和 KMT-2024-BLG-1209Lb：通过弱焦散穿越信号探测到的微引力透镜行星 显示英文标题

标题： MOA-2022-BLG-091Lb and KMT-2024-BLG-1209Lb: Microlensing planets detected through weak caustic-crossing signals

摘要： 微引力透镜事件MOA-2022-BLG-091和KMT-2024-BLG-1209的光变曲线显示出具有非常相似特征的异常现象。这些异常现象出现在光变曲线的峰值附近，在该处增益适度较高，并通过弱焦散穿越特征与最小失真区分，同时光源仍位于焦散区域内。为了更深入地理解这些异常现象，我们对透镜事件进行了全面分析。我们进行了二元透镜建模，并对参数空间进行了彻底探索。这一分析揭示了这两个事件中的异常现象均源自行星起源，尽管由于不同类型的退化，其确切解释较为复杂。就MOA-2022-BLG-091而言，对异常现象解释的主要困难源于新识别出的退化问题，即与光源轨迹与行星宿主轴相交角度的不确定性相关。对于KMT-2024-BLG-1209，解释受到已知的内-外退化的干扰，导致源在相对行星宿主通过内或外焦散区域时产生解决方案之间的歧义。贝叶斯分析表明，这两个透镜系统的行星均为质量约为木星2到4倍的巨行星，围绕早期K型主序星运行。这两个系统很可能位于银河盘中，距离约为4千秒差距。KMT-2024-BLG-1209中的退化难以解决，因为它源自退化解的焦散结构的内在相似性。相比之下，MOA-2022-BLG-091中的退化是偶然发生的，而非固有特性所致，预计未来基于太空的罗马RGES微引力透镜巡天将能够解决这一问题。 显示英文摘要

摘要： The light curves of the microlensing events MOA-2022-BLG-091 and KMT-2024-BLG-1209 exhibit anomalies with very similar features. These anomalies appear near the peaks of the light curves, where the magnifications are moderately high, and are distinguished by weak caustic-crossing features with minimal distortion while the source remains inside the caustic. To achieve a deeper understanding of these anomalies, we conducted a comprehensive analysis of the lensing events. We carried out binary-lens modeling with a thorough exploration of the parameter space. This analysis revealed that the anomalies in both events are of planetary origin, although their exact interpretation is complicated by different types of degeneracy. In the case of MOA-2022-BLG-091, the main difficulty in the interpretation of the anomaly arises from a newly identified degeneracy related to the uncertain angle at which the source trajectory intersects the planet-host axis. For KMT-2024-BLG-1209, the interpretation is affected by the previously known inner-outer degeneracy, which leads to ambiguity between solutions in which the source passes through either the inner or outer caustic region relative to the planet host. Bayesian analysis indicates that the planets in both lens systems are giant planets with masses about 2 to 4 times that of Jupiter, orbiting early K-type main-sequence stars. Both systems are likely located in the Galactic disk at a distance of around 4 kiloparsecs. The degeneracy in KMT-2024-BLG-1209 is challenging to resolve because it stems from intrinsic similarities in the caustic structures of the degenerate solutions. In contrast, the degeneracy in MOA-2022-BLG-091, which occurs by chance rather than from inherent characteristics, is expected to be resolved by the future space based Roman RGES microlensing survey.