Modeling the Nearly Isotropic Comet Population in Anticipation of LSST Observations

TL;DR

This study uses simulations to predict the distribution of nearly isotropic comets in the outer solar system, emphasizing LSST's potential to detect and analyze these comets, which originate from the Oort Cloud and inform solar system formation.

Contribution

It provides the first detailed prediction of NIC orbital distributions detectable by LSST, linking observations to the structure of the Oort Cloud and solar system formation history.

Findings

LSST will detect hundreds to thousands of NICs.

NICs originate from the outer Oort Cloud and are dynamically excluded from the inner solar system.

Orbital characterization is more precise when comets are observed far from the Sun.

Abstract

We run simulations to determine the expected distribution of orbital elements of nearly isotropic comets (NICs) in the outer solar system, assuming that these comets originate in the Oort Cloud at thousands of AU and are perturbed into the planetary region by the Galactic tide. We show that the Large Synoptic Survey Telescope (LSST) should detect and characterize the orbits of hundreds to thousands of NICs with perihelion distance outside 5 AU. Observing NICs in the outer solar system is our only way of directly detecting comets from the inner Oort Cloud, as these comets are dynamically excluded from the inner solar system by the giant planets. Thus the distribution of orbital elements constrains the spatial distribution of comets in the Oort cloud and the environment in which the solar system formed. Additionally, comet orbits can be characterized more precisely when they are seen far from the Sun as they have not been affected by non-gravitational forces.