Cometography: A Catalog of Comets. Series: Cometography. Vol. 1
On the Babylonian cuneiform tablet designated BMA 41131, Hermann Hunger identified references to a comet seen during the year -119. An observation dated May 18 says, “…a comet in the path of (the stars of) […].” An observation on May 20 says, “…when the comet became stationary to the east….” A June 16th observation says the comet’s tail was directed southward. Finally, an observation dated July 13 says, “…beginning of the night, the comet which had [appeared(?)] in the east(?) on the 29th day of month I(?) in Aries in the path of (the stars of) Anu […].” This last statement indicates the comet was apparently in Aries when seen on May 18, indicating the comet was originally in the morning sky.
The annals of the text Han shu (100) is the oldest Chinese document to have reported this object. It notes that in -119, “in the spring, there was a sparkling star in the eastern quarter of the sky.” An eastern location could imply a morning sky observation.
The Roman historian Marcus Junianus Justinus wrote Epitome, an abridgment of the Historiae Philippicae et totius mundi origines et terrae situs by Pompeius Trogus during the 3rd century (the work of Trogus no longer exists). In one part Justinus states that at the time Mithradates VI Eupator began his reign as king of Pontus in northern Anatolia “a comet burned so brightly for 70 days that the entire sky seemed to be on fire. In its greatness it filled a quarter of the heavens, and with its brilliance it outshone the sun, while its rising and setting each took a period of four hours.” The same description is also applied to a comet that appeared in the year of the birth of Mithradates VI Eupator, which was noted earlier under the comet X/-134 N1.
The dates of this comet’s appearance are firmly established by the Babylonians as May 18 to July 13. The Chinese certainly add support by noting the comet appeared during the Spring. The Roman account of Justinus is admittedly not precisely dated, but its statement of a visibility of 70 days at least indicates a long-duration comet. Typically, it is rare for a comet to attain naked-eye visibility for such a long period of time, so the Author believes the Roman account agrees well enough with the Babylonian duration of 56 days to assume they are probably describing the same comet.
A.G. Pingré (1783) only knew of the Chinese comet and listed it as appearing in -120, but noted the year could have been -119.