《元史·本纪·卷四》
世祖中统二年春，正月初九夜间，东北方有一赤色气团，光亮照人，大如一床席子。
二年春正月辛未夜，东北赤气照人，大如席。
In the spring of the second year of Emperor Shizu's Zhongtong reign, on the night of the ninth day of the first lunar month, a reddish air mass appeared in the northeast, shining brightly and as large as a mattress.