SETI bioastro: Stability Limits in Extra-solar Planetary Systems

From: LARRY KLAES (ljk4_at_msn.com)
Date: Fri Jul 14 2006 - 10:39:32 PDT

  • Next message: LARRY KLAES: "SETI bioastro: Planetesimal formation via fragmentation in self-gravitating protoplanetary disc"

    Astrophysics, abstract
    astro-ph/0607210

    From: Rory Barnes [view email]

    Date: Tue, 11 Jul 2006 00:16:11 GMT (41kb)

    Stability Limits in Extra-solar Planetary Systems

    Authors: Rory Barnes, Richard Greenberg

    Comments: 13 pages, 4 figures, accepted ApJ Letters

    Two types of stability boundaries exist for any planetary system consisting
    of one star and two planets. Lagrange stability requires that the planets
    remain bound to the star, conserves the ordering of the distance from the
    star, and limits the variations of orbital elements like semi-major axis and
    eccentricity. Hill stability only requires that the ordering of the planets
    remain constant; the outer planet may escape to infinity. A simple formula
    defines a region in orbital element space that is guaranteed to be Hill
    stable, although Hill stable orbits may lie outside the region as well. No
    analytic criteria describe Lagrange stability. We compare the results of
    1000 numerical simulations of planetary systems similar to 47 UMa and HD
    12661 with these two types of boundaries. All cases are consistent with the
    analytic criterion for Hill stability. Moreover, the numerically determined
    Lagrange boundary lies close to the analytic boundary for Hill stability.
    This result suggests an analytic formulation that may describe the criterion
    for Lagrange stability.

    http://arxiv.org/abs/astro-ph/0607210


  • Next message: LARRY KLAES: "SETI bioastro: Planetesimal formation via fragmentation in self-gravitating protoplanetary disc"

    This archive was generated by hypermail 2.1.6 : Fri Jul 14 2006 - 10:44:36 PDT