[1] He worked for a long time at the Nice Observatory.
In astronomy, Hénon is well known for his contributions to stellar dynamics.
He developed a numerical technique using Monte Carlo methods to follow the dynamical evolution of a spherical star cluster much faster than the so-called n-body methods.
In mathematics, he is well known for the Hénon map, a simple discrete dynamical system that exhibits chaotic behavior.
He published a two-volume work on the restricted three-body problem.