4:45 PM - 5:00 PM
[PPS03-12] Origin of Small Solar System Bodies with Hyperbolic Orbits
Keywords:interstellar objects, Oort cloud, hyperbolic orbits
In this paper, we study the dynamical aspect of objects in hyperbolic orbits from the two different sources: interstellar and from the Oort cloud. We analytically derive the numbers of objects with given orbital element (eccentricity and perihelion distance) for each source. By comparing the numbers of the interstellar objects coming into the Solar system and the Oort cloud comets injected by passing stars, we can estimate which origin is more favorable for the object observed with the given v and b (i.e., e and q). For the orbital elements of 1I/2017 U1 (e ~ 1.19 and q ~ 0.25 au), we conclude that the possibility of having an interstellar origin is higher than that of an Oort cloud origin unless the Solar system had recently experienced close encounter with a star, which is unlikely.