Speaker
Description
We summarized our simulation results of the short-term dynamical evolution on 500 numbered Short-Period Comets over a 2000-year window (between 1000 and 3000 A.D.). To understand their evolution history, we classified the comets we studied into several groups based on the dynamical features: the recent semi-major/perihelion (a/q) jump, the Tisserand parameter reversion, and the temporary satellite captured by Jupiter.
We confidently identify 6214 planet-encounter events on 458 comets in 555k cometo-years, with impact distances smaller than 3 Hill radii of the planet. Statistical results for encounter distance and the change in each orbital element will be given. The Tisserand parameter indicates which planet a minor object is gravitationally bound to. We found two types of Tisserand reversion—fast and slow—marking orbital transfers between the Jupiter and Saturn domains. The fast Tisserand reversion occurs at the planet's encounter and results in a sudden, significant orbital change, whereas the slow reversions do not. We find that objects undergoing "fast" reversion frequently overlap with those experiencing recent a/q jumps, suggesting they are "fresh" Jupiter-Family Comets (JFCs) recently migrated into the inner solar system. Notably, three new Temporarily Satellite Captured (TSC) comets are identified (345P, 441P, 467P) in this study.
Crucially, we find a potential correlation between these dynamical histories and cometary chemistry. None of the "low-activity" comets identified in previous surveys (Ye et al. 2016) qualify as fresh JFCs in our model. Furthermore, our identified fresh JFCs consistently fall into the low-carbon/OH groups (A’Hearn et al. 1995). While the sample size is limited, we need more observational evidence for the possible connection and to explain the physical interpretation.
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