Join us for the WiCOR Research Seminar from Prof. Konstantin Batygin (Professor of Planetary Science, Division of Geological & Planetary Sciences, Caltech) presented at the Department of Astronomy’s Monday Science Seminar!

Title: Coda of a Dying Sun

Abstract:

From its birth, celestial mechanics has been deeply intertwined with the question of the Solar System’s dynamical stability. For the inner planets, this question is now statistically settled: Mercury’s orbit carries roughly a 1 percent chance of destabilization before the Sun leaves the main sequence. The outer Solar System has seemed more secure, with an intrinsic dynamical lifetime estimated at approximately 10^18 years. Even accounting for solar mass loss and stellar flybys, the orbital architecture of the giant planets has been expected to persist for roughly 100 billion years.

Here, we show that these estimates rest on the assumption that solar mass loss is smooth. The recently measured recoil of white dwarfs instead points to asymmetric mass loss, most readily attributed to discrete, independently directed ejections that impulsively perturb stellar motion. As the Sun sheds its envelope in such parcels, the planetary orbits undergo a random walk whose amplitude is determined by the granularity of the mass loss. For granularity consistent with observationally permitted kicks, this stochastic forcing restructures the outer Solar System concurrently with the Sun’s death.

Our numerical experiments reveal that orbit crossing can begin on the red giant branch, with roughly 40 percent of realizations undergoing disruption or violent scattering before the white dwarf forms and roughly 90 percent self-destructing within 3 billion years. The dynamical lifetime of the outer Solar System thus collapses from approximately 10^18 years to about a billion years after white dwarf formation.

Speaker Bio:

Professor Konstantin Batygin is a theoretical astrophysicist whose research explores the formation and evolution of planetary systems over their full lifetimes. He also studies exoplanets and the physical processes that shape planetary interiors and atmospheres. Batygin received his bachelor’s degree in astrophysics from UC Santa Cruz in 2008 and pursued his graduate studies at Caltech. After holding a prize postdoctoral fellowship at Harvard University, he joined the Caltech faculty in 2014. He has been the recipient of numerous awards, including a Sloan Research Fellowship, a Packard Fellowship in Science and Engineering, and, most recently, the inaugural Ginsburg Prize. He was also named to Forbes’ 30 Under 30 list and, unlike a surprising number of his fellow honorees, has not yet been indicted. In his free time, he moonlights as a singer and guitarist for the rock band The Seventh Season.

https://www.konstantinbatygin.com

Accommodations:

WiCOR is committed to creating an inclusive and accessible event. If you need a reasonable accommodation, please contact Vanessa Orr, WiCOR Administrative Manager, at wicor@wisc.edu. All requests must be made by Sept 7. We will attempt to implement late requests but cannot guarantee they will be met.