Title: Post-Runaway Gas Giant Formation


Abstract: Runaway gas accretion from a protoplanetary disk is thought to be a key phase of gas giant planet formation. This instability comes to a halt as growing planets carve density cavities (gaps) in their surrounding disks. I will describe this final phase of planet formation, when planets accrete through the gap and simultaneously cool and contract. Our fully time-dependent theory consistently couples the growth of the planet, its contraction, and the opening of the gap. I will compare the theory to two sets of novel observations of directly imaged planets: luminosities of planets still embedded in gas disks, and rotational line broadening from high resolution planet spectra. The theory and observations of post-runaway formation may explain how many of the properties of giant planets, such as their mass and spin, are set during this final phase.