First light adaptive optics images from the Keck II Telescope: A new era of high angular resolution imagery

Adaptive optics (AO) is a technology that corrects in real time for the blu rring effects of atmospheric turbulence, in principle allowing Earth-bound telescopes to achieve their diffraction limit and to "see" as clearly as if they were in space. The power of AO using natural guide stars has been amp ly demonstrated in recent years on telescopes up to 3-4 m in diameter. The next breakthrough in astronomical resolution was expected to occur with the implementation of AO on the new generation of large, 8-10 m diameter teles copes. In this paper we report the initial results from the first of these AO systems, now coming on line on the 10 m diameter Keck II Telescope. The results include the highest angular resolution images ever obtained from a single telescope (0." 022 and 0." 040 at 0.85 and 1.65 mu m wavelengths, re spectively), as well as tests of system performance on three astronomical t argets.