Hyperbolic comets as an indicator of a hypothetical planet 9 in the solar system

Abstract

In this study, we assess whether a dynamic relationship exists between hyperbolic comets (HCs) with osculating orbit elements and a hypothetical planet 9 (HP9). We have found strong statistical evidence that HCs and parabolic comets are two independent sets of long-periodic comets; thus, HCs can be used as an independent set in this analysis. We have applied numerical integration, minimal orbit intersectional distance (MOID) calculations, close encounter phenomena, and the descending and ascending node distributions of comets to investigate the possible dynamic relationship between planet candidates and HCs. Transitions between the two groups (from a hyperbolic orbit to a parabolic orbit or vice versa) of these comets require a strong perturbation from a massive body. Notable clusters have been obtained for the descending and ascending node distributions of HCs for distances of 250–300 AU and 200–250 AU with respect to the ecliptic, accordingly, and for distances of 260–400 AU relative to the predicted HP9 plane at Ωp = 2710.6 and ip = 840.3. These clusters may arise from perturbations caused by HP9 near these distances.Our findings show that the MOID values of 30 comets are lower than the Hill sphere radius of HP9 sub-models. The changing eccentricity of comet C/2007J A21 (LINEAR) and its close encounter with the orbit of the HP9 sub-model were demonstrated by numerical integration and MOID calculation methods. We also assessed the possible dynamic perturbation of HCs caused by massive trans-Neptunian objects using MOID value analysis.