NBIA Colloquium: Andrew Youdin

Speaker: Andrew Youdin (University of Arizona)

Title: The Core Accretion Hypothesis: The Standard Model of Planet Formation and Its Open Questions

Abstract: The core accretion hypothesis provides a unified framework for the formation of minor planets, terrestrial planets, and gas giants. In this picture, dust grains grow into planetesimals, which build up into larger rocky and icy protoplanets. Those that grow massive enough, and quickly enough, can accrete gas envelopes. I will discuss the support for this theory from the Solar System and exoplanet systems, as well as its challenges and the alternatives that have been proposed. I will conclude with recent work on gas accretion onto protoplanets, highlighting open questions about the transition from terrestrial planets to gas giants.

Brief Bio-sketch: Dr. Andrew Youdin is a theoretical astrophysicist who studies planet formation, from planetesimals to giant planets, and the dynamics of the disks in which planets form. His theoretical work is motivated by and connected to observations of Solar System bodies, exoplanet systems, and protoplanetary disks. He received a PhD in Physics from UC Berkeley and held postdoctoral and research positions at Princeton, CITA/University of Toronto, the Harvard-Smithsonian Center for Astrophysics, and CU Boulder before joining the faculty of Steward Observatory at the University of Arizona. He is now a full professor with joint appointments in Planetary Sciences and Applied Mathematics and leads the Planet Formation Initiative within the Theoretical Astrophysics Program.

Refreshments in the NBIA Lounge after the talk!