AI 中文总结
本研究通过显微镜评估历史照相底片上的两个多暂现源候选体，发现其特征与短时间闪光相符，为历史暂现现象研究提供了结合显微镜与档案分析的概念验证框架。
AI 中文摘要
我们对在历史照相底片上识别出的两个多暂现源候选体的代表性案例开展了基于显微镜的评估：1950年4月12日的九暂现源事件（XE325）和1952年7月19日的三暂现源事件（XE186）。这些事件由在单次长曝光底片上探测到的空间聚集的点状源组成，不存在运动天体应有的拖尾，因此暗示是短时间闪光。我们分析了原始玻璃底片材料、独立拷贝底片以及档案元数据的显微镜图像，并将这些图像与已发表的巡天数字化结果进行配准，以便定位各个编目源。在这两个案例中，候选体看起来比典型恒星点扩散函数略锐利、更致密，定性上与约50分钟曝光期间的亚秒至数秒发射相符，且它们在同一天区的不同成像形式中可重复，这排除了数字化 artifact 的起源。不过，单个点状特征的显微镜分析本身无法区分短时间闪光与乳胶本征缺陷，因为两种场景在单源层面产生的信号定性相似。我们还表明，多台站视差测试虽原则上有效，但由于缺乏达到相当深度的同时性第二台站底片，对于这两个特定事件无法实施。我们得出结论，要解决这些事件的本质问题，需要总体统计，且在未来观测允许的情况下，需采用专门构建的多台站成像。本工作为结合显微镜与档案分析研究历史暂现现象提供了概念验证框架。
英文摘要
We present a microscopy-based assessment of two representative cases of multiple-transient candidates identified on historical photographic plates: the nine-transient event of 12 April 1950 (XE325) and the triple-transient event of 19 July 1952 (XE186). These events consist of spatially clustered, point-like sources detected within single long-exposure plates, lacking the streaks expected from moving objects and therefore suggestive of short-duration flashes. We analyse microscopy images of the original glass-plate material together with an independent copy plate and archival metadata, and we register these images against the published survey digitizations so that individual catalogued sources can be located. In both cases the candidates appear slightly sharper and more compact than typical stellar point spread functions, qualitatively consistent with sub-second to few-second emission during exposures of $\sim 50$~min, and they are reproducible across different representations of the same field, which disfavours a digitization-artifact origin. However, microscopy of individual point-like features cannot by itself separate a short-duration flash from an intrinsic emulsion defect, because the two scenarios produce qualitatively similar signatures at the single-source level. We also show that the multi-observatory parallax test, while powerful in principle, is not feasible for these two specific events with presently available material, owing to the absence of a simultaneous second-site plate reaching comparable depth. We conclude that resolving the nature of these events requires population-level statistics and, where future observations allow, purpose-built multi-station imaging. This work provides a proof-of-concept framework for combining microscopy with archival analysis in the study of historical transient phenomena.
