Gregorian telescope (English, noun)
expansion: Gregorian telescope (plural Gregorian telescopes)
Senses:
glosses: A type of reflecting telescope having two concave mirrors: the primary mirror (a paraboloid) collects the light and brings it to a focus before the secondary mirror (a ellipsoid), where it is reflected back through a hole in the centre of the primary, and thence out the bottom end of the instrument, where it can be viewed with the aid of the eyepiece.
Forms:
form: Gregorian telescopes
tags: plural