  We consider the planar central configurations of the Newtonian $\kappa
n$-body problem consisting in $\kappa$ groups of $n$-gons where all $n$ bodies
in each group have the same mass, called $(\kappa, n)$-crown. We study the
location and the number of central configurations when $\kappa=2$. For $n=3$
the number of central configurations varies depending on the mass ratio,
whereas for $n\geq 4$ the number is at least three. We also prove that for
$n\geq 3$ there always exist three disjoint regions where the configuration can
be located. Finally, we study which $(\kappa, n)$-crowns are convex.
