author={Arika Higuchi and Eiichiro Kokubo},
  journal={The Astronomical Journal},
We have investigated the effect of stellar encounters on the formation and disruption of the Oort cloud using the classical impulse approximation. We calculate the evolution of a planetesimal disk into a spherical Oort cloud due to the perturbation from passing stars for 10 Gyr. We obtain the empirical fits of the e-folding time for the number of Oort cloud comets using the standard exponential and Kohlrausch formulae as functions of the stellar parameters and the initial semimajor axes of… 

Galactic tide and local stellar perturbations on the Oort cloud: creation of interstellar comets

Comets in the Oort cloud evolve under the influence of internal and external perturbations, such as giant planets, stellar passages, and the Galactic gravitational tidal field. We aim to study the

Anisotropy of Long-period Comets Explained by Their Formation Process

  • A. Higuchi
  • Physics, Geology
    The Astronomical Journal
  • 2020
Long-period comets coming from the Oort cloud are thought to be planetesimals formed in the planetary region on the ecliptic plane. We have investigated the orbital evolution of these bodies due to

Effects of inclined star-disk encounter on protoplanetary disk size

Most, if not all, young stars are initially surrounded by protoplanetary disks. Owing to the preferential formation of stars in stellar clusters, the protoplanetary disks around these stars may

Oort cloud Ecology

Jan Hendrik Oort hypothesized the existence of a distant cloud of cometary objects that orbit the Sun based on a spike in the reciprocal orbital separation at 1∕a  ≲  10−4 au−1. The Oort cloud is the

Origin and Evolution of Long-period Comets

We develop an evolutionary model of the long-period comet (LPC) population, starting from their birthplace in a massive trans-Neptunian disk that was dispersed by migrating giant planets. Most comets

Long-period comets as a tracer of the Oort cloud structure

A previous study showed that a fingerprint of the initial shape of synthetic Oort clouds was detectable in the flux of “new” long-period comets. The present study aims to explain in detail how such a

Chaos in the inert Oort cloud

Context. Distant trans-Neptunian objects are subject to planetary perturbations and galactic tides. The former decrease with the distance, while the latter increase. In the intermediate regime where

Long-term orbital dynamics of trans-Neptunian objects

  • M. Saillenfest
  • Physics, Geology
    Celestial Mechanics and Dynamical Astronomy
  • 2020
This article reviews the different mechanisms affecting the orbits of trans-Neptunian objects, ranging from internal perturbations (planetary scattering, mean-motion resonances, and secular effects)

Long-term orbital dynamics of trans-Neptunian objects

This article reviews the different mechanisms affecting the orbits of trans-Neptunian objects, ranging from internal perturbations (planetary scattering, mean-motion resonances, and secular effects)



Injection of Oort Cloud comets: the fundamental role of stellar perturbations

We present Monte Carlo simulations of the dynamical evolution of the Oort cloud over the age of the Solar System, using an initial sample of one million test comets without any cloning. Our model

Stellar perturbations of the cometary cloud

The existence of a cloud of ∼2 × 1011 comets surrounding the Solar System and extending out to interstellar distances has been suggested by Oort1 based on the observed distribution of inverse

Scattering of Planetesimals by a Planet: Formation of Comet Cloud Candidates

We have investigated the first dynamical stage of comet cloud formation, the scattering of planetesimals by a planet. The orbits of planetesimals were calculated using circular restricted three-body

Embedded star clusters and the formation of the Oort Cloud

Oort cloud formation at various Galactic distances

In this study we present the results from numerical simulations of the formation of the Oort comet cloud where we positioned the Sun in various parts of the disc of the Galaxy, starting at 2 kpc up

Stellar perturbations on the scattered disk

We present a statistical model for estimating the effects of stellar encounters on orbits in the outer Solar System, focussing on the scattered disk at <10 3 AU from the Sun. We describe a Monte

Algorithms for Stellar Perturbation Computations on Oort Cloud Comets

A sequential variant of Dybczyński’s approach is introduced, cutting the encounter into several steps whereby the heliocentric motion of the comet is taken into account, and found to offer an efficient means to obtain accurate results for practically any domain of the parameter space.

The Formation and Extent of the Solar System Comet Cloud

The formation of the solar system comet cloud and its subsequent evolution over an interval equal to the age of the solar system are simulated. Assuming that the comets formed in the outer planetary

Stellar encounters with the solar system

We continue our search, based on Hipparcos data, for stars which have encountered or will encounter the solar system (Garcia-Sanchez et al. [CITE]). Hipparcos parallax and proper motion data are