VASAO: Visible All Sky Adaptive Optics - , A new adaptive optics concept for CFHT
O. Lai, C. Veillet, D. Salmon, K. Ho, M. Baril, G. Barrick, J.P. Pique

Abstract: Still in the feasibility study stage, VASAO is an ambitious project that, will explore new conceptual direction in the field of astronomical adaptive, optics. , , In the era of 8 meter and larger telescopes, and their instrument, costs and telescope time pressure, there is a natural niche for such, ground-breaking conceptual development in the 4 meter class telescopes., The ultimate aim of VASAO is to provide diffraction limited imaging in, the visible with 100%25 sky coverage; the challenge arises from the simultaneity, of these requirements, although many exciting astrophysical cases can already, be made with an all-sky infrared system as an intermediate step. , To this end, CFHT has started a feasibility study based on the , polychromatic guide star concept (Foy etal, 1995) coupled with a high , order curvature AO system., , Because such a project straddles such a fine line between facility instrument, and experimental facility, careful thought will have to be given to the balance, between modes of operations and potential astrophysical targets, to maximize its, usefulness.,