Gregorian telescope
noun
Forms Gregorian telescopes
- noun 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.
Synonyms
Etymology
Designed by Scottish mathematician and astronomer James Gregory in the 17th century.
Sources: Wiktionary · WordNet 3.0 — from the Wiktionary entry “Gregorian telescope”, CC BY-SA 4.0. Details