Astronomy Colloquium

Planets show a remarkable diversity of physical and orbital traits spanning over four orders of magnitude in mass, separation, and age.   Making sense of these discoveries is challenging, as observational incompleteness and orbital migration complicate the broader picture of when and where planets form and how they dynamically evolve across space (orbital separation) and time (from Myrs to Gyrs).  This story is far from complete but is beginning to come into focus for some populations—particularly giant planets.  High-contrast imaging has opened up much of this landscape from the outside in, enabling a powerful probe of the orbits, atmospheres, rotation periods, dynamical masses, obliquities, and circumplanetary accretion disks of long-period gas giants.  I will share progress from my group surveying giant planets across space and time with an emphasis on recent ground- and space-based results to establish how planets transition from the earliest phases of growth through gas accretion to their longer-term, dynamically rich outcomes.  I will end with my hopes (and fears) for filling in these details with astrometry from Gaia—which is poised to uncover thousands of planets—new instruments on existing facilities, and the forthcoming era of Extremely Large Telescopes.