Vol. 576
In section 10. Planets and planetary systems

The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system

Using the LMIRCam camera on the Large Binocular Telescope, Maire et al. obtain accurate astrometric measurements for the planetary system around HR 8799. Their results agree with predictions based on available data and theoretical arguments that the 4 planets are in a 8:4:2:1 configuration. Another possible configuration with three planets in a 4:2:1 resonance and the innermost pair in a 5:2 resonance is ruled out with 2-sigma significance. Further studies of this most intriguing system should cast new light on the formation and dynamical evolution of giant planets at tens of astronomical units from their parent stars.