Reanalysis of radial velocity data from the resonant planetary system HD128311

Abstract

The multi-planetary system HD128311 hosts at least two planets. Its dynamical formation history has been studied extensively in the literature. We reanalyse the latest radial velocity data for this system with the affine-invariant Markov chain Monte Carlo sampler EMCEE. Using the high order integrator IAS15, we perform a fully dynamical fit, allowing the planets to interact during the sampling process. A stability analysis using the MEGNO indicator reveals that the system is located in a stable island of the parameter space. In contrast to a previous study, we find that the system is locked in a 2:1 mean motion resonance. The resonant angle ${\phi }_1$ is librating with a libration amplitude of approximately 37°. The existence of mean motion resonances has important implication for planet formation theories. Our results confirm predictions of models involving planet migration and stochastic forces.

4 pages, 2 figures, accepted by MNRAS Letters

References in corpus (7)

• Mean motion resonances from planet-planet scattering
• Influence of an inner disc on the orbital evolution of massive planets migrating in resonance
• On the evolution of mean motion resonances through stochastic forcing: Fast and slow libration modes and the origin of HD128311
• On the evolution of the resonant planetary system HD128311
• Stability and Formation of the Resonant System HD 73526
• Secondary resonances of co-orbital motions
• On fitting planetary systems in counter-revolving configurations

Cited by in corpus (4)

• Astrometry with Hubble Space Telescope Fine Guidance Sensors - A Review
• Tatooine's Future: The Eccentric Response of Kepler's Circumbinary Planets to Common-Envelope Evolution of their Host Stars
• A Pair of Planets Likely in Mean-motion Resonance From Gravitational Microlensing
• Inferred Properties of Planets in Mean-Motion Resonances are Biased by Measurement Noise