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  2. Adaptive optics - Wikipedia

    en.wikipedia.org/wiki/Adaptive_optics

    Adaptive thin shell mirror. [5]Adaptive optics was first envisioned by Horace W. Babcock in 1953, [6] [7] and was also considered in science fiction, as in Poul Anderson's novel Tau Zero (1970), but it did not come into common usage until advances in computer technology during the 1990s made the technique practical.

  3. Diaphragm (optics) - Wikipedia

    en.wikipedia.org/wiki/Diaphragm_(optics)

    The Hamburg Observatory-Bergedorf location had a 60 cm (~23.6 inch) aperture Great Refractor by Reposold and Steinheil (Lenses). [10] One unique feature of the Hamburg Great Refractor is an iris diaphragm that allows the aperture to be adjusted from 5 to 60 cm. [11] This telescope was activated in the early 1910s. [11]

  4. Optical telescope - Wikipedia

    en.wikipedia.org/wiki/Optical_telescope

    The Large Binocular Telescope at the Mount Graham International Observatory in Arizona uses two curved mirrors to gather light. An optical telescope is a telescope that gathers and focuses light mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct visual inspection, to make a photograph, or to collect data through electronic image sensors.

  5. Telescope - Wikipedia

    en.wikipedia.org/wiki/Telescope

    A larger aperture does not just mean that more light is collected, it also enables a finer angular resolution. Telescopes may also be classified by location: ground telescope, space telescope, or flying telescope. They may also be classified by whether they are operated by professional astronomers or amateur astronomers.

  6. Astronomical seeing - Wikipedia

    en.wikipedia.org/wiki/Astronomical_seeing

    The telescope used had a diameter of about 7r 0 (see definition of r 0 below, and example simulated image through a 7r 0 telescope). Twinkling of the brightest star of the night sky Sirius (apparent magnitude = -1,1) in the evening shortly before culmination on the southern meridian at a height of 20 degrees above the horizon. During 29 seconds ...

  7. Aperture - Wikipedia

    en.wikipedia.org/wiki/Aperture

    In some contexts, especially in photography and astronomy, aperture refers to the opening diameter of the aperture stop through which light can pass. For example, in a telescope, the aperture stop is typically the edges of the objective lens or mirror (or of the mount that holds it). One then speaks of a telescope as having, for example, a 100 ...

  8. David L. Fried - Wikipedia

    en.wikipedia.org/wiki/David_L._Fried

    The turbulence causes what is known as seeing in astronomy and usually limits the optical resolution of ground-based telescopes and the detail in their images of astronomical objects. The Fried Parameter describes the smallest diameter of a telescope aperture at which the image fidelity starts to suffer significantly from turbulent airflows in ...

  9. Extremely large telescope - Wikipedia

    en.wikipedia.org/wiki/Extremely_large_telescope

    Comparison of nominal sizes of apertures of the above extremely large telescopes and some notable optical telescopes. An extremely large telescope (ELT) is an astronomical observatory featuring an optical telescope with an aperture for its primary mirror from 20 metres up to 100 metres across, [1] [2] when discussing reflecting telescopes of optical wavelengths including ultraviolet (UV ...