Adaptive optics

When we observe a star with the naked eye we have the impression that it twinkles. Nevertheless the star does not emit fluctuating light. This apparent twinkling in fact results from a perturbation brought about by the luminous rays crossing the atmosphere. Adaptive optics is a technique born in the 1990s which allows such non-predictable distortions of the observations to be corrected in real time, thanks to telescopes equipped with deformable mirrors which are capable of compensating atmospheric turbulence exactly.