College of Science

Women in Physics SEMINAR: Smadar Naoz [UCLA]

On the Dynamics of Planets, Stars and Black Holes - New Insights from Triples

May 11, 2017 11:00 AM to May 11, 2017 12:00 PM at

Many observed triple systems in our Universe are in a hierarchical configuration: two objects orbit each other in a relatively tight inner binary while the third object is on a much

wider orbit. Furthermore, the secular (long-term, average) approximation for the evolution of hierarchical triple-body systems has been proven to be very useful in many astrophysical contexts, from planetary to triple-star systems and even black holes.I will discuss recent developments that showed that considering systems beyond the test particle approximation, or circular orbits, requires the next level of approximation for a correct representation of the physics called the octupole-level. This leads to qualitative different behavior of the system. Most interestingly, at this level of approximation, for an eccentric wide orbit, the tight orbit can reach extremely high eccentricities and undergo chaotic flips of its orientation. This behavior has important implications for the evolution of many systems, and I will present some nominal examples, such as retrograde hot Jupiters, blue stragglers, and low-mass X-ray binaries.


This seminar is part of a newly established series of talks related to Women in Physics, organized and led by Dr. Nina Abramzon from the Department of Physics and Astronomy.