Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-19T09:19:56.652Z Has data issue: false hasContentIssue false
  • English
  • Français

Dynamical evolution of Oort cloud comets to near-Earth space

Published online by Cambridge University Press:  01 August 2006

Olga A. Mazeeva
Olga A. Mazeeva*
Affiliation:
Department of Computational and Celestial Mechanics, South Ural State University, Chelyabinsk, 454080, Russia email: omega@susu.ac.ru
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The dynamical evolution of 2⋅105 hypothetical Oort cloud comets by the action of planetary, galactic and stellar perturbations during 2⋅109 years is studied numerically. The evolution of comet orbits from the outer (104 AU <a<5⋅104 AU, a is semimajor axes) and the inner Oort cloud (5⋅103 AU <a<104 AU) to near-Earth space is investigated separately. The distribution of the perihelion (q) passage frequency in the planetary region is obtained calculating the numbers of comets in every interval of Δ q per year. The flux of long-period (LP) comets (orbital periods P>200 yr) with perihelion distances q<1.5 AU brighter than visual absolute magnitude H10=7 is ∼ 1.5 comets per year, and ∼18 comets with H10<10.9. The ratio of all LP comets with q<1.5 AU to ‘new’ comets is ∼5. The frequency of passages of LP comets from the inner Oort cloud through region q<1.5 AU is ∼3.5⋅10−13 yr−1, that is roughly one order of magnitude less than frequency of passages of LP comets from the outer cloud (∼5.28⋅10−12 yr−1). We show that the flux of ‘new’ comets with 15<q<31 AU is higher than with q<15 AU, by a factor ∼1.7 for comets from the outer Oort cloud and, by a factor ∼7 for comets from the inner cloud. The perihelia of comets from the outer cloud previously passed through the planetary region are predominated in the Saturn-Uranus region. The majority of inner cloud comets come in the outer solar system (q>15 AU), and a small fraction (∼0.01) of them can reach orbits with q<1.5 AU. The frequency of transfer of comets from the inner cloud (a<104 AU) to the outer Oort cloud (a>104 AU), from where they are injected to the region q<1.5 AU, is ∼6⋅10−14 yr−1.

Keywords

Oort Cloudcomets: generalsolar system: general
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 2 , Symposium S236: Near Earth Objects, our Celestial Neighbors: Opportunity and Risk , August 2006 , pp. 43 - 54
Copyright
Copyright © International Astronomical Union 2007

References

Bailey, M.E. & Stagg, C.R. 1988, MNRAS 235, 1CrossRefGoogle Scholar
Dones, L., Levison, H.F., Duncan, M. & Weissman, P. 2000, BAAS 32, 1060Google Scholar
Duncan, M., Quinn, T. & Tremaine, S. 1987, AJ 94, 1330CrossRefGoogle Scholar
Dybczynski, P.A. 2001, Astron. Astrophys. 375, 643CrossRefGoogle Scholar
Emel'yanenko, V.V. 1999, Evolution and source regions of asteroids and comets, Proc. IAU Coll. 173, p. 339Google Scholar
Fernandez, J.A. 1981, Astron. Astrophys. 96, 26Google Scholar
Fernandez, J.A. 2002, Earth, Moon & Planets 89, 325CrossRefGoogle Scholar
Francis, P.J. 2005, AJ 635, 1348CrossRefGoogle Scholar
Heisler, J. & Tremaine, S. 1986, Icarus 65, 13CrossRefGoogle Scholar
Heisler, J., Tremaine, S. & Alcock, C. 1987, Icarus 70, 269CrossRefGoogle Scholar
Hills, J.G. 1981, AJ 86, 1730CrossRefGoogle Scholar
Levison, H.F., Morbidelli, A., Dones, L., Jedicke, R., Wiegert, P.A. & Bottke, W.F. 2002, Science 296, 2212CrossRefGoogle Scholar
Marsden, B.G., Sekanina, Z. & Everhart, E. 1978, AJ 83, 64CrossRefGoogle Scholar
Marsden, B.G. & Williams, G.V. 2005, Catalogue of Cometary OrbitsGoogle Scholar
Ogorodnikov, K.F. 1965, Dynamics of stellar systems (Oxford: Pergamon)Google Scholar
Oort, J.H. 1950, Bull. Astron. Inst. Neth. 11, 91Google Scholar
Weissman, P.R. 1993, BAAS 25, 1063Google Scholar
Weissman, P.R. 1996, Completing the Inventory of the Solar System, ASP Conf. Ser. 107, p. 265Google Scholar