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SEQUENCE:1
UID:UW-Physics-Event-9854
DTSTART:20260921T170000Z
DTEND:20260921T180000Z
DTSTAMP:20260918T083634Z
LAST-MODIFIED:20260914T135402Z
LOCATION:WiCOR Space\, 6515 Sterling Hall
SUMMARY:Coda of a Dying Sun\, WiCOR/Astronomy Monday Science Seminar\,
  Konstantin Batygin\, Professor\, Division of Geological & Planetary S
 ciences\, Caltech
DESCRIPTION:From its birth\, celestial mechanics has been deeply inter
 twined with the question of the Solar System’s dynamical stability. 
 For the inner planets\, this question is now statistically settled: Me
 rcury’s orbit carries roughly a 1 percent chance of destabilization 
 before the Sun leaves the main sequence. The outer Solar System has se
 emed more secure\, with an intrinsic dynamical lifetime estimated at a
 pproximately 10^18 years. Even accounting for solar mass loss and stel
 lar flybys\, the orbital architecture of the giant planets has been ex
 pected to persist for roughly 100 billion years.<br>
\n<br>
\nHere\, w
 e show that these estimates rest on the assumption that solar mass los
 s is smooth. The recently measured recoil of white dwarfs instead poin
 ts to asymmetric mass loss\, most readily attributed to discrete\, ind
 ependently 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 per
 mitted kicks\, this stochastic forcing restructures the outer Solar Sy
 stem concurrently with the Sun’s death.<br>
\n<br>
\nOur numerical e
 xperiments reveal that orbit crossing can begin on the red giant branc
 h\, with roughly 40 percent of realizations undergoing disruption or v
 iolent 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 a
 bout a billion years after white dwarf formation.
URL:https://www.physics.wisc.edu/events/?id=9854
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