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Thread: Regions for planets in triple systems

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    Default Regions for planets in triple systems



    Past items italicized. Scopes: Refractors: Orion ST80 (mods for while light solar), SV ED80 f7, Orion and SW 80 and 120 ED doublets; Newtonians: AT 8”f4, OC 8”f6.3, Z12 f5, self made 6” f9, Orion XX14i; Catadioptrics: VMC110L, Intes MK66, Celestron 9.25 SCT and 9.25 Edge. EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, TV Nagler, ES100s.

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    Default Re: Regions for planets in triple systems

    One annoyance with the paper..... it's very casual in the use of "stability". We don't know that the solar system is stable. Computer simulations are only capable of showing "relative stability".
    MCox, SPlains and michael131313 like this.
    Past items italicized. Scopes: Refractors: Orion ST80 (mods for while light solar), SV ED80 f7, Orion and SW 80 and 120 ED doublets; Newtonians: AT 8”f4, OC 8”f6.3, Z12 f5, self made 6” f9, Orion XX14i; Catadioptrics: VMC110L, Intes MK66, Celestron 9.25 SCT and 9.25 Edge. EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, TV Nagler, ES100s.

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    Default Re: Regions for planets in triple systems

    Quote Originally Posted by not_Fritz_Argelander View Post
    One annoyance with the paper..... it's very casual in the use of "stability". We don't know that the solar system is stable. Computer simulations are only capable of showing "relative stability".
    Yes, no one that has ever done a three-body simulation should believe in “stability”.
    Michael Cox
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    for my other "hobby"

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    Default Re: Regions for planets in triple systems

    I am not an expert in astrodynamical stability, but the 1-10 million year timeframe used for the simulations seems quite short.

    For comparison, Saturn's "surprisingly youthful" rings are a few hundred million years old. An "incredibly young" exoplanet found recently is in a system that is 5-10 million years old. That suggests 5-10 million years is the minimum time duration for something to even exist when discussing solar system bodies. Claiming "stability" will require simulations over a timeframe that is some multiple of this time duration.

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    Default Re: Regions for planets in triple systems

    Integrating the non linear equations of motion is not practical for even the Solar System for more than 20,000,000 years. Because the equations of motion are nonlinear one needs to know the initial conditions (positions, velocities, now for instance) extremely well. With all we know, we cannot compute out positions longer than that. The measurement errors compound unacceptable.
    chas53 likes this.
    Past items italicized. Scopes: Refractors: Orion ST80 (mods for while light solar), SV ED80 f7, Orion and SW 80 and 120 ED doublets; Newtonians: AT 8”f4, OC 8”f6.3, Z12 f5, self made 6” f9, Orion XX14i; Catadioptrics: VMC110L, Intes MK66, Celestron 9.25 SCT and 9.25 Edge. EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, TV Nagler, ES100s.

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