Orbital Fitting and Analysis of HR8799 Using GRAVITY High Precision Astrometry

HR8799 is a young planetary system containing four super-Jupiters that have been well-monitored with a variety of instruments for a substantial number of years. This is the only directly imaged system for which we observe more than two substellar companions- presenting a unique study of planet-planet interactions through astrometric measurements of high enough precision. The continuation of high precision monitoring of HR8799 allows us to more accurately model the motion of these exoplanets and constrain their orbital parameters to smaller uncertainties. With a better understanding of their assumed orbital dynamics, inferences about these planets’ formation processes can be made from properties such as eccentricity that trace differences between formation methods. This project utilizes five years of observations from the near-infrared, high precision interferometric instrument, GRAVITY, on the Very Large Telescope Interferometer. GRAVITY provides precision astrometry at the 10 micro arcsecond level and has the potential to induce significant constraint on the orbit models for HR8799. In this poster, I outline the streamlined data reduction method used to recalculate GRAVITY astrometric measurements, present the newest constraints on the orbital parameters of all four planets, report their coplanarity, and provide an analysis of how this system evolved to its current configuration.