International Workshop On Comets In Honor of Hans Rickman

Session

The dynamic of comets

17 mai 2016, 10:15

Amphitheater Building 18 (Meudon site)

Présidents de session

The dynamic of comets

• Alessandro Morbidelli

The dynamic of comets

• Christiane Froeschlé

The dynamic of comets

• Christiane Froeschlé

The dynamic of comets

• Nicolas Biver

The dynamic of comets: The dynamic of comets

• Nicolas Biver

The dynamic of comets

• Antonella Barucci

21. Probing the Oort Cloud with Centaurs

Nathan Kaib (University of Oklahoma)

17/05/2016 10:15

The dynamic of comets

Talk

The Oort cloud has previously been invoked to explain observations of centaurs with very high inclinations and/or very large semimajor axes since such orbits are difficult to generate from the scattered disk. However, the known sample of centaurs has been detected with a combination of surveys with different observational biases, some more well-characterized than others. Consequently, it is...

10. The relative contribution of the Oort cloud and the scattered disc to the short-period comet population

Prof. Vacheslav Emel'yanenko (Institute of Astronomy, RAS)

17/05/2016 11:00

The dynamic of comets

Talk

We discuss how many comets come to short-period orbits from different sources in the outer solar system. The observed distribution of Centaurs, as a transition population, plays a pivotal role in constraining our models. We show that the Oort cloud and the scattered disc produce similar numbers of Jupiter-family comets.

11. Increasing knowledge and understanding of dynamical history of the observed Oort spike comets

Dr Piotr A. Dybczyński (Astronomical Observatory Institute, faculty of physics, A.Mickiewicz Univ., Poznań, Poland)

17/05/2016 14:00

The dynamic of comets

Talk

Galactic and stellar perturbations are important factors when studying the past and future motion of the observed Oort spike comets. Since our knowledge on the Solar System Galactic environment is continuously increasing it is necessary to upgrade our methods and computer codes for taking into account these perturbations in a proper way. I will report our preparations to incorporate new...

16. Warsaw Catalogue of long-period comets

Małgorzata Królikowska (SRC PAS)

17/05/2016 14:45

The dynamic of comets

Talk

Currently, this Catalogue includes orbits of about 160 Oort spike comets defined as objects with original 1/a less than 0.000100 au$^{-1}$. Orbits were determined or redetermined in a completely homogeneous way and constitute more than 85% of the Oort spike comets discovered before 2010. In the publicly available Catalogue, we offer observed (i.e. osculating orbit at the epoch close to the...

9. Oort cloud and Scattered Disc formation during an episode of giant planet instability

Dr Brasser Ramon (Institute for Astronomy and Astrophysics, Taiwan)

17/05/2016 16:00

The dynamic of comets

Talk

I discuss how the proposed instability of the giant planets that sculpted the Kuiper Belt and Scattered Disc also formed the Oort comet cloud. I show the results of numerical simulations of this problem and discuss formation efficiency, number of comets in the cloud and the Oort cloud to Scattered Disc population ratios. I compare these with observations and give an updated estimate based...

22. Oort Cloud evolution in a long-lived stellar cluster

Hans Rickman (Uppsala University)

17/05/2016 16:45

The dynamic of comets

Talk

Solar type stars typically form as members of embedded clusters, which dissolve on different time scales depending on their masses and densities. Most such clusters are small and short-lived, and Oort Cloud (OC) formation has often been modeled within such a scenario. But Lada & Lada (2003) showed that about equal numbers of stars are formed in clusters with populations of 10^2, 10^3 and 10^4...

3. The Oort cloud: shape and dynamics

Marc Fouchard

18/05/2016 09:15

The dynamic of comets

Talk

We will present our last results on the long term dynamics of the Oort cloud comets. It particular the final shape of the Oort cloud and its dependency on the initial condition sample will be investigated. The relations between the final shape and present flux of observable "new" long period comets are also highlighted.

7. Long period comet encounters with the planets: an analytical approach

Giovanni Valsecchi (IAPS-INAF)

18/05/2016 10:00

The dynamic of comets

Talk

Close encounters with the giant planets play an important role in the evolution of the orbits of long period comets, and have been treated in a number of papers. We revisit the subject in the framework of an analytic theory of close encounters, that provides useful insight on the properties of the strong perturbations caused by planetary encounters.

28. On the existence of comet families in extrasolar planetary system

Prof. Rudolf Dvorak (Universite de Vienne, Autriche)

18/05/2016 11:15

The dynamic of comets

Talk

We investigate whether there can exist comet families in the extrasolar planetary systems Kepler 90 and HD 10180, systems which consist of six planets; the outermost is a giant. This is done by extensive numerical integrations of millions of hypothetical comets entering the inner system on almost hyperbolic orbits. The goal is to find whether families like the Halley comets or the Jupiter...

23. The role of comets in the Late Heavy Bombardment

Hans Rickman (PAS Space Research Center, Warszawa, Poland)

19/05/2016 17:00

The dynamic of comets

Talk

We have simulated the orbital evolution of icy planetesimals ("comets") in the inner solar system upon dispersal of the primordial planetesimal disk by giant planet migration as prescribed by the Nice Model. Using both the assumption of non-evolving comets and models including erosion by sublimation and splitting, we have estimated the impact rate and crater formation due to these comets on...