Over the past three decades, we have witnessed one of the great revolutions in our
understanding of the cosmos—the dawn of the Exoplanet Era. Where once we knew of just …

With four companions at separations from 16 to 71 au, HR 8799 is a unique target for direct
imaging, presenting an opportunity for a comparative study of exoplanets with a shared …

The four directly imaged planets orbiting the star HR 8799 are an ideal laboratory to probe
atmospheric physics and formation models. We present more than a decade's worth of …

Context. Direct imaging of extrasolar giant planets demands the highest possible contrasts
(ΔH≳ 10 mag) at the smallest angular separations (∼ 0.1 ″) from the star. We present an …

HR 8799 hosts four directly imaged giant planets, but none has a mass measured from first
principles. We present the first dynamical mass measurement in this planetary system …

The exoplanetary system of HR 8799 is one of the rare systems in which multiple planets
have been directly imaged. Its architecture is strikingly similar to that of the solar system, with …

Context. HR 8799 is a young planetary system composed of four planets and a double
debris belt. Being the first multi-planetary system discovered with the direct imaging …

The HR 8799 system hosts four massive planets orbiting 15 and 80 au. Studies of the
system's orbital stability and its outer debris disk open the possibility of additional planets …

A system of four super-Jupiter planets around HR 8799 is the first multiplanet configuration
discovered via the direct imaging technique. Despite over a decade of research, the …

The dust production in debris discs by grinding collisions of planetesimals requires their
orbits to be stirred. However, stirring levels remain largely unconstrained, and consequently …