Event #207: Guest Star, Nova, observed by Chinese

The Han shu (100) is the oldest text to report his object. Alt says a “guest star”, was seen by the Chinese sometime during the “first watch of the night” an -68 July 23. The object “stayed between the left and the right star of Chio [(α and, ζ Virginis], pointing southeastward and measuring about 2º. Its color was white.”

The date and location indicate it was in the evening sky, implying a UT of July 23.6.A. G. Pingré (1783) listed this observation with the comet seen in August -68. During 1846, Édouard C. Biot suggested this object was a nova, while Benjamin Peirce independently suggested this object was an early observation of the August comet and even computed an uncertain orbit to link the available observations (see comet 109P/-68 Q1). Adolf Berberich later expressed his opinion that this was an observation of a meteor train. I. Hasegawa (1980) said the July object was “probably not the same” as the August object. This opinion was proven true in 1992 when the August observations were linked to 109P/Swift-Tuttle.

69 BC, July 23, China. A white guest star measuring 3 degrees and pointing southeast appeared and remained above Spica in Virgo. Possibly, this was a nova.

1st year of the Dijie reign period of Emperor Xuan of the Han Dynasty, 6th month, day wuxu [35], first watch of the night; a white guest star about 2 chi long again stayed between Zuojiao and Youjiao [LM 1], pointing southeast.