Text #39Cometography: A Catalog of Comets. Series: Cometography. Vol. 1 .
The only ancient source of information on this comet is the Shih chi (-90). It says a “broom star” was seen sometime during -237, which “possibly stretched across the heavens.” This statement was discussed prior to a record listed in the fourth month, which could imply the event happened either during or before the lunar month of May 4 to June 2. The Shih chi later noted, “This month was frigid,” and continued, “A comet appeared in the west, and again in the north, moving southwards toward the (Nan-) Tou [ζ, λ, μ, σ, τ, and φ Sagittarii] and lasted 80 days.” This translation is similar to that by Ho Peng Yoke (1962) and I. Hasegawa (1980). Interestingly, two people have recently translated the account slightly differently. Instead of moving southwards toward Sagittarius, Burton Watson (SC1993 #2) and William H. Nienhauser, Jr (SC1994) independently said the account claimed the comet “moved southwards from the Dipper for 80 days.” The “Dipper” apparently referred to Pei-Tou [the Big Dipper].
Earlier accounts do not solve the translation problem. A.G. Pingré (1783) wrote that this comet appeared in May near Sagittarius, while J. Williams (1871) said the object “was also seen in the north, to the south of Pei-Tou, for 80 days.”
Full moon: April 18, May 17