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Cassegrain telescope

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noun Cas·se·grain telescope \ ˈka-sə-ˌgrān- \

variants: or less commonly Cassegrain or Cassegrainian telescope play \ˌka-sə-ˈgrā-nē-ən-\

Definition of Cassegrain telescope

:a reflecting telescope that has a paraboloidal primary mirror and hyperboloidal secondary mirror, is equivalent in its optical effects to a telephoto lens, and usually has the light brought to a focus through a perforation in the center of the primary mirror

Origin and Etymology of cassegrain telescope

after Laurent Cassegrain †1693 French priest and teacher credited with its invention

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First Known Use: 1806

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