Tip-tilt wavefront corrector for large-sized CCD cameras

摘要

A tip-tilt wavefront (image displacement) corrector has been designed and fabricated to increase the efficiency of direct imaging with large-sized CCD cameras. A plane-parallel glass plate tilting in two mutually perpendicular directions at an angle large enough to compensate for an image displacement of +/- 16 '' on a telescope with F approximate to 20 m forms the basis of the device. The device allows up to approximate to 20 corrections per second to be made when a similar to 14(m) reference star is used. We investigate the effects of aberrations introduced by the plate on the image quality. We present the results of test observations with the corrector performed on the 1.25-m ZTE telescope at the Crimean Station of the Sternberg Astronomical Institute and the 1.5-m AZT-22 telescope at the Maidanak Observatory, where test images with 1-h exposures that completely realized atmospheric seeing were obtained.