PHOTOMETRY WITH ADAPTIVE OPTICS : A FIRST GUIDE TO EXPECTED PERFORMANCE

This paper aims to help prospective observers estimate the likely performance of adaptive optics for pho- tometric observations. Both real and simulated adaptive optics data are used in specic examples covering the ma- jor observational situations. These illustrate the dier- ent sources of uncertainty: seeing fluctuations, presence of both a large halo and residual fluctuations in the point spread function, and angular anisoplanatism. The astro- nomical cases studied include isolated sources, faint struc- tures around a star, and crowded stellar elds. The photo- metric performance image deconvolution is also examined. No attempt is made to investigate exhaustively all possi- ble atmospheric conditions and observing congurations, but the discussion should be a useful guide to the feasibil- ity of using adaptive optics in astronomical programmes requiring particular photometric accuracies.