Equilibrium points and basins of convergence in the triangular
  restricted four-body problem with a radiating body
  The dynamics of the four-body problem have attracted increasing attention in
recent years. In this paper, we extend the basic equilateral four-body problem
by introducing the effect of radiation pressure, Poynting-Robertson drag, and
solar wind drag. In our setup, three primaries lay at the vertices of an
equilateral triangle and move in circular orbits around their common center of
mass. Here, one of the primaries is a radiating body and the fourth body (whose
mass is negligible) does not affect the motion of the primaries. We show that
the existence and the number of equilibrium points of the problem depend on the
mass parameters and radiation factor. Consequently, the allowed regions of
motion, the regions of the basins of convergence for the equilibrium points,
and the basin entropy will also depend on these parameters. The present
dynamical model is analyzed for three combinations of mass for the primaries:
equal masses, two equal masses, different masses. As the main results, we find
that in all cases the libration points are unstable if the radiation factor is
larger than 0.01 and hence able to destroy the stability of the libration
points in the restricted four-body problem composed by Sun, Jupiter, Trojan
asteroid and a test (dust) particle. Also, we conclude that the number of fixed
points decreases with the increase of the radiation factor.
