Institute for Advanced Study Astrophysics Seminar

ABSTRACT: Recent observations have shown that in many exoplanetary systems, the spin axis of the parent star is misaligned with the angular momentum axis of the planet's orbit. This is unexpected as planets are formed in protostellar disks which are thought to be perpendicular to the stellar rotation axis. Surprisingly, the interaction between a magnetic protostar and its circumstellar disk gives rise to a secular instability, which may result in spin-orbit misalignment following planet formation, even before any additional few-body gravitational interaction takes place.