Testing of a Stellar Interference Coronagraph as Part of a Ground-Based Telescope

Direct exoplanet imaging with a stellar coronagraph increases the contrast of the image in the diffraction vicinity of the star. Insufficient reduction of the stellar background is due to the required quality of the wavefront, which exceeds the capabilities of modern optical and astronomical systems. This study evaluates the achievable coronagraphic contrasts for ground-based and extra-atmospheric telescopes without the use of adaptive optics (AO); further, it is planned to use AO devices: tip-tilt mirror and pixel-based AO for the correction of the zonal error. For practical testing of a prospective multicircuit telescope system with active wavefront-correcting optics, we constructed a coronagraph with a small telescope aperture, which makes it possible to observe the effect of coronagraphic attenuation of a star. The latter is important for the testing of precision guidance of the star by the automated parallax drive of the telescope to construct a practical sequence of the operation of adaptive optics devices. The errors of the wavefront inside the interference coronagraph were estimated, experiments were commenced, and line of sight retention was obtained.