"Orbits and Atmospheres of Directly Imaged Exoplanets"

 

 

 

 

Directly imaged exoplanets offer a new window into the rapidly evolving field of planet formation and evolution. The ability to separate the light of widely separated planets (~5 - 100 AU) from their host stars is extremely advantageous for studying Jovian planets. The combination of dynamical and atmospheric characterization can give essential clues about how these planetary systems form. To demonstrate this new insight, I will discuss results from an ongoing monitoring campaign of the HR 8799 directly imaged multi-planet system using the Keck Observatory adaptive optics system. High precision astrometry (~1 mas) has provided constraints on the orbital properties of the four HR8799 planets. Moderate resolution (R~4000) spectroscopy has given precise estimates of the planets' effective temperature, surface gravity, and chemical composition. By analyzing the implied atmospheric chemisty, we have found tantalizing clues about the possible formation pathway for this planetary system. I will also discuss new results from the Gemini Planet Imager (GPI), an instrument specifically designed to image and characterize young, widely separated Jovian planets. I will describe the first planet discovered with GPI, 51 Eridani b, which is likely the lowest mass exoplanet imaged to date. Finally, I will discuss the ongoing GPI Exoplanet Survey (GPIES) and how it will continue to revolutionize our understanding of this fascinating planet population.