322P/SOHO: The counterpart of a historical comet in 254 CE?

Abstract

The historical observations of East Asia provide a systematic and accurate record of bright periodic comets and could help us understand their past states. However, except for these comets, few other comets have been successfully associated with historical observations. Here we report that the sunskirter 322P/SOHO is probably associated with a historical comet in 254 CE, although it appeared no visible cometary activity in recent observations. By analyzing astrometric data from the IAU Minor Planet Center, we determine the orbit of 322P and suggest that its motion is affected by non-gravitational forces based on sodium sublimation, indicating its high devolatilization. The orbital integration shows that the position and perihelion date of 322P are highly corresponding to a historical comet in 254 CE. This comet had an extremely long tail that stretched across the sky, indicating the intense activity outburst. The dynamical properties of 322P and its similarity to dark comets suggests that it possibly originated from a volatile object in the main belt, but has undergone the rotational splitting and devolatilization. Previous studies have also suggested the possible splitting. Given that splitting is a common cause of activity outburst, we suggest that 322P might have experienced a fragmentation in 254 CE and released a large amount of material, which led to the spectacular tail and devolatilization. Only faint sodium-driven activity remained afterwards, which could explain the lack of historical observations after 254 CE.