White vapour to the north, Kaifeng, 13 December 1052

Songshi astronomical treatise, catalogued by Hayakawa et al. 2015 as an aurora candidate. White colour, direction north, length 5 zhang (in Chinese sky measure 1 zhang is roughly 10 degrees, so very roughly 50 degrees of sky; an earlier note here wrongly said about 15), moon phase 0.66, observed at Kaifeng, latitude 34.8 north. White vapours are the weakest class of aurora candidate; a northern white glow can also be a comet tail, zodiacal light or cloud.