  In this paper we classify the central configurations of the circular
restricted 4-body problem with three primaries at the collinear configuration
of the 3-body problem and an infinitesimal mass. The case where the three
primaries have the same mass, with one of the bodies staying motionless at the
center of mass, was considered in 2021 by Llibre. The video
\url{https://youtu.be/PWFtqxd4RUA} goes over some of the results in this paper.
