Let F\mathcal{F} be a family of star bodies in R ⁿ (compact bodies in R ⁿ with nonempty kernels). A function s: F\mathcal{F} F\mathcal{F} provided that s(A) F\mathcal{F} . To every star body A and every : [0,) [0,) we assign a function _A: ker A R defined in terms of the radial function of translates of A. We prove that if A is convex and is concave and strictly increasing, then _A has a unique maximizer, which is referred to as the radial center of A induced by (Theorem 3.1). We extend the radial center map over some family of star bodies (Theorem 4.2). Further, we define a suitable metric, _st , the star metric, on the family of all the compact star sets in R ⁿ . This new metric is topologically stronger than the Hausdorff metric (Theorem 5.7). We study the continuity of our selectors with respect to _st .