TITLE:
Invariant Manifolds near $L_1$ and $L_2$ in the Sun-Jupiter
Elliptic Restricted Three-Body Problem II. The dynamics
of comet Oterma

AUTHORS:
Gladston Duarte^(1) and Angel Jorba^(2,3)

(1) Dipartimento di Ingegneria Meccanica e Aerospaziale,
    Politecnico di Torino,\newline
    Via Duca degli Abruzzi 24, 10129, Torino, Italy.
(2) Departament de Matem{\`a}tiques i Inform{\`a}tica,
    Universitat de Barcelona,\newline
    Gran Via de les Corts Catalanes 585, 08007 Barcelona, Spain.
(3) Centre de Recerca Matemàtica, Edifici C, Campus Bellaterra,
     08193 Bellaterra, Spain

E-mails: gladston.duarte@polito.it, angel@maia.ub.es

ABSTRACT:
Comet 39P/Oterma is known to make fast transitions between
heliocentric orbits outside the orbit of Jupiter and heliocentric
orbits inside that of Jupiter.  In this paper, the dynamics of comet
Oterma is modelled and fitted in the Planar Elliptic RTBP.  Using the
computations presented in \cite{DuarteJ23b} we look for the invariant
objects around $L_1$ and $L_2$, which in the case of the Planar
Elliptic RTBP are invariant tori and their stable and unstable
manifolds, that are the skeleton that guides Oterma in its rapid
transition.