Convergent Migration Renders TRAPPIST-1 Long-lived

Daniel Tamayo, Hanno Rein, Cristobal Petrovich, Norman Murray
(Submitted on 10 Apr 2017 (v1), last revised 8 May 2017 (this version, v2))

TRAPPIST-1 is a late M-dwarf orbited by seven Earth-sized planets with orbital period ratios near a chain of mean motion resonances. Due to uncertain system parameters, most orbital configurations drawn from the inferred posterior distribution are unstable on short timescales of $\sim$ 0.5 Myr, even when including the eccentricity damping effect of tides. By contrast, we show that most physically plausible resonant configurations generated through disk migration are stable even without tidal dissipation on timescales of at least 50 Myr ($10^{10}$ orbits), an increase of at least two orders of magnitude. This result, together with the remarkable chain of period ratios in the system, provide strong evidence for convergent migration naturally emplacing the system near an equilibrium configuration forced by the resonant chain. We provide an openly available database of physically plausible initial conditions for TRAPPIST-1 generated through parametrized planet-disk interactions, as well as bit-by-bit reproducible N-body integrations over $10^9-10^{10}$ orbits.

Comments:    7 pages 5 figures. Accepted in ApJ Letters. Scripts to visualize the dataset and reproduce the figures in this manuscript are available at this https URL
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
Cite as:    arXiv:1704.02957 [astro-ph.EP] (or arXiv:1704.02957v2 [astro-ph.EP] for this version)
Submission history
From: Daniel Tamayo
[v1] Mon, 10 Apr 2017 17:26:38 GMT (156kb,D)
[v2] Mon, 8 May 2017 15:27:49 GMT (159kb,D)
http://lanl.arxiv.org/abs/1704.02957
Astrobiology