What we wanted to check in this
work is the fate of particles subjected to gas-drag. We wanted to
know if, for the case of Kiviuq, the librating solutions might be
an attractor. For this purpose, we first integrated 20 particles
in the region of transition between circulation and libration bacward in
time under the influence of gas-drag, to find the moment when they become
circulating. We computed the average values of a,e,i and \Theta,
at
that moment, and generated a grid of initial conditions to cover the libration
island for that value of \Theta. Here we report the plot of
the orbital elements of one of our particles:
And this are the average values of a,e,i,and \Theta for our 20 particles:
<a> = 0.13832 AU, <e>= 0.51, <i> = 55.15o, <\Theta> = 0.24
We then integrate our particles forward in time with a
typical value of gas density at mid-disk of 6*10-9 g/cm3
and plot the particle fate at t = 200 yr and t = 4000 yr. These
are the results:
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As can be seen in the left part of the plot, circulating
particles tend indeed to become librating.
Here we report the evolution of particles on circulating,
"chaotic", and librating orbits, from the left and right part of the panel.
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