A Search for Encke’s Comet in Ancient Chinese Records: A Progress Report

Abstract

The catalog by Ho Peng Yoke lists ancient Chinese observations of 581 transient astronomical objects of which some 300 might conceivably have been P/Encke, between the years – 156 and + 1600. Using the Gauss-Hill method it was possible to establish roughly the plane of the orbit and the direction of perihelion for P/Encke over this interval of time. All but about 40 of the objects could be eliminated by comparing the observed locations with possible locations of P/Encke. Several more could be eliminated on the basis of their calculated magnitudes and general observability. Large uncertainties in the non-Newtonian motion as yet prevent our certain identification of P/Encke among the remaining possibilities.