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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

NEW! Time Traveler

First Known Use: 1806

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