Named in honor of Jacques Henrard (1940– ), professor of mathematics at the University of Namur. Henrard has applied algorithms based on Hamiltonian and Lie formalisms, particularly to the motions of the moon, the Galilean satellites of Jupiter and artificial satellites. With his celestial mechanics research group, which he formed in 1971, Henrard extended the adiabatic-invariant and action-angle theory and introduced it as a practical tool. He has also worked on the theory of slow chaotic motion and has been intensively involved in modeling mean-motion resonances in the asteroid belt. Since 1989 he has been editor-in-chief of the journal Celestial Mechanics. (M 27461) _ _.