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We present an analysis of Kitt Peak National Observatory and LowellObservatory observations of comet 103P/Hartley 2 obtained from August throughDecember 2010. The results are then compared with contemporaneous observationsmade by the EPOXI spacecraft. Each ground-based dataset has previously beeninvestigated individually; the combined dataset has complementary coverage thatreduces the time between observing runs and allows us to determine additionalapparent periods at intermediate times. We compare CN coma morphology betweenground-based datasets, making nine new measurements of apparent periods. Thefirst five are consistent with the roughly linearly increasing apparent periodduring the apparition found by previous authors. The final four suggest thatthe change in apparent period slowed or stopped by late November. We alsomeasure an inner coma lightcurve in both CN and R-band ground-based images,finding a single-peaked lightcurve which repeats in phase with the comamorphology. The apparent period from the lightcurve had significantly largeruncertainties than from the coma morphology, but varied over the apparition ina similar manner. Our ground-based lightcurve aligns with the published EPOXIlightcurve, indicating that the lightcurve represents changing activity ratherthan viewing geometry of structures in the coma. The EPOXI lightcurve can bestbe phased by a triple-peaked period near 54-55 hr that increases from Octoberto November. This phasing reveals that the spacing between maxima is notconstant, and that the overall lightcurve shape evolves from one triple-peakedcycle to the next. These behaviors suggest that much of the scatter in apparentperiods derived from ground-based datasets acquired at similar epochs arelikely due to limited sampling of the data.

A Further Investigation of Apparent Periodicities and the Rotational  State of Comet 103P/Hartley 2 from Combined Coma Morphology and Lightcurve  Datasets