Event #36: Circumpolar Sparkling Star in Hydra observed by Chinese

The Chinese text Han shu (100) is the oldest record of this object. It says a “sparkling star” was seen at Chang [κ, λ, μ, ν1, and ν2 Hydrae] sometime during the month of -137 April 9 to May 7. The object was then said to pass the T’ai-wei Enclosure [Coma Berenices, Leo, and Virgo], trespass against the Tzu-wei enclosure [Draco, Ursa Minor, Cepheus and Camelopardalis], and reach the Milky Way. Both A.G. Pingré (1783) and J. Williams (1871) erroneously dated this as March.

Although apparently situated toward the evening sky when first seen, the comet’s movement into the Thai-wei Enclosure would have made it visible almost all night long. It would have remained visible throughout the night when it became circumpolar by moving into the Tzu-wei Enclosure.

Full moon: April 23

138 BC, April, China, a bushy star comet appeared in Hydra, and traveled north through the north polar region until reaching the Milky Way.

3rd year of the Jianyuan reign period of Emperor Wu of the Han Dynasty, 3rd month; a star became fuzzy in Zhu [LM 24] and Zhang [26] that passed through Taiwei, interfered with Zigong, and reached the Milky Way.