Abstract. While graphical records of astronomical/meteorological events before telescopic observations are of particular interest, they have frequently undergone multiple instances of copying and may have been modified from the original. Here, we analyse a graphical record of the cross sign of 806 CE in the Anglo-Saxon Chronicle (ASC), which has been considered one of the earliest datable halo drawings in British records, whereas another cross sign in 776 CE has been associated with the aurora. However, philological studies have revealed the later 806 event is derived from continental European annals. Here, records and drawings for the 806 event have been philologically traced back to mid-ninth-century continental European manuscripts (MSS) and the probable observational site identified as the area of Sens in northern France. The possible lunar halos at that time have been comprehensively examined by numerical ray tracing. Combined with calculations of twilight sky brightness, they identify a visibility window supporting monastic observation. Cruciform halos are shown to be fainter and rarer than brighter and more commonplace lunar halos. Physically credible cloud ice crystal variations can reproduce all the manuscript renditions. The manuscript records prove less-than-desirable detail, but what is presented is fully consistent with a lunar-halo interpretation. Finally, the possible societal impacts of such celestial events have been mentioned in the context of contemporary coins in Anglo-Saxon England and the Carolingian Empire. These analyses show that we need to trace their provenance back as far as possible, to best reconstruct the original event, even if graphical records are available for given astronomical/meteorological events.

中文翻译：

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《盎格鲁—撒克逊纪事》中806十字符号的出处：欧洲大陆上可能有月球晕吗？

摘要。虽然在望远镜观测之前的天文/气象事件的图形记录特别令人关注，但它们经常经历了多次复制，并且可能已从原始副本进行了修改。在这里，我们分析了盎格鲁-撒克逊纪事报（ASC）中806 CE十字符号的图形记录，该图形被认为是英国记录中最早的数据光晕图形之一，而776 CE中的另一个十字符号则与极光。但是，语言学研究表明，后来的806事件是源自欧洲大陆的纪事。在这里，806事件的记录和图纸从文字上追溯到九世纪中叶的欧洲大陆手稿（MSS）和可能​​的观测地点，被确定为法国北部的Sens地区。通过数值射线追踪对当时可能出现的月晕进行了全面研究。结合黄昏天空亮度的计算，它们确定了支持修道院观测的可见度窗口。十字形的光晕比更明亮，更常见的月球光晕更暗淡，稀少。物理上可靠的云冰晶变体可以复制所有手稿。手稿记录证明细节不尽人意，但所呈现的内容与月球-晕轮解释完全一致。最后，在英格兰盎格鲁撒克逊人和加洛林帝国的当代钱币背景下，提到了这种天体事件可能产生的社会影响。这些分析表明，我们需要尽可能追溯其起源，以最好地重建原始事件，