TITLE:
Families of Halo-like invariant tori around $L_2$ in the
Earth-Moon Bicircular Problem

AUTHORS:
Jos\'e J. Rosales, Angel Jorba and Marc Jorba-Cusco
Universitat de Barcelona

E-mails: rosales@maia.ub.es, angel@maia.ub.es, marc@maia.ub.es

ABSTRACT:
The Bicircular Problem (BCP) is a periodic time dependent perturbation
of the Earth-Moon Restricted Three-Body Problem that includes the 
direct gravitational effect of the Sun. In this paper we use the BCP 
to study the existence of Halo-like orbits around $L_2$ in the 
Earth-Moon system taking into account the perturbation of the Sun. By
means of computing families of 2D invariant tori, we show that there
are at least two different families of Halo-like quasi-periodic orbits
around $L_2$.