English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report constraints on the three-dimensional orbital architecture for allfour planets known to orbit the nearby M dwarf Gliese 876 based solely onDoppler measurements and demanding long-term orbital stability. Our datasetincorporates publicly available radial velocities taken with the ELODIE andCORALIE spectrographs, HARPS, and Keck HIRES as well as previously unpublishedHIRES velocities. We first quantitatively assess the validity of the planetsthought to orbit GJ 876 by computing the Bayes factors for a variety ofdifferent coplanar models using an importance sampling algorithm. We find thata four-planet model is preferred over a three-planet model. Next, we apply aNewtonian MCMC algorithm to perform a Bayesian analysis of the planet massesand orbits using an n-body model in three-dimensional space. Based on theradial velocities alone, we find that a 99% credible interval provides upperlimits on the mutual inclinations for the three resonant planets($\Phi_{cb}<6.20^\circ$ for the "c" and "b" pair and $\Phi_{be}<28.5^\circ$ forthe "b" and "e" pair). Subsequent dynamical integrations of our posteriorsample find that the GJ 876 planets must be roughly coplanar($\Phi_{cb}<2.60^\circ$ and $\Phi_{be}<7.87^\circ$), suggesting the amount ofplanet-planet scattering in the system has been low. We investigate thedistribution of the respective resonant arguments of each planet pair and findthat at least one argument for each planet pair and the Laplace argumentlibrate. The libration amplitudes in our three-dimensional orbital modelsupports the idea of the outer-three planets having undergone significant pastdisk migration.

An Empirically Derived Three-Dimensional Laplace Resonance in the Gliese 876 Planetary System