Adaptive optics aims to compensate for the distortions caused by atmospheric turbulence, which degrades the quality of astronomical images.

Atmospheric distortions are primarily caused by variations in temperature, pressure, wind currents, and the presence of aerosols and dust particles, which lead to fluctuations in the refractive index of the atmosphere.

Seeing refers to the rapidly changing distortions in the atmosphere that cause variations in the image quality of astronomical observations.

Adaptive optics involves measuring the wavefront distortions caused by atmospheric turbulence and using a deformable mirror to compensate for these distortions in real time.

Shack-Hartmann, curvature, and pyramid wavefront sensors are commonly used devices for measuring wavefront distortions in adaptive optics systems.

The deformable mirror in adaptive optics is used to correct the wavefront distortions introduced by atmospheric turbulence by changing its shape in real time.

The isoplanatic patch is the region of the atmosphere where the wavefront distortions are relatively constant, allowing adaptive optics to effectively compensate for them.

Stars benefit the most from adaptive optics correction because they are point sources and their images are most affected by atmospheric turbulence.

Implementing adaptive optics systems for large telescopes poses challenges in terms of the cost of deformable mirrors, the complexity of wavefront sensors, and the need for fast computational processing to handle the large amount of data.

Keck Observatory, Gemini Observatory, and Subaru Telescope are among the observatories that have successfully implemented adaptive optics systems.

Adaptive optics improves the angular resolution of telescopes by reducing the effects of atmospheric turbulence, which allows for sharper and more detailed images.

Wavefront reconstruction is the process of estimating the wavefront distortions from the measurements obtained by wavefront sensors.

Deformable mirrors used in adaptive optics systems typically have a size of a few centimeters.

Multi-conjugate adaptive optics systems are used to correct for large-scale wavefront distortions by using multiple deformable mirrors.

Tomographic adaptive optics systems can correct for anisoplanatism, which is the variation of wavefront distortions across the field of view.