Gregorian telescope

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.

Similar
Cassegrainian telescope
Ask AI about this wordChatGPTClaudePerplexityGoogle AIGrok

Meanings

nounGregorian telescope (plural Gregorian telescopes)

plural Gregorian telescopes

  1. 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 & antonyms

nouna reflecting telescope that has a paraboloidal primary mirror and a hyperboloidal secondary mirror; light is brought to a focus through an aperture in the center of the primary mirror

Similar
Cassegrainian telescope
Broader
reflecting telescopereflector

Synonym sets from Open English WordNet, CC BY 4.0.

Origin

Designed by Scottish mathematician and astronomer James Gregory in the 17th century.

Full word history & related roots →
Cite this entry
APA

Gregorian telescope. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Gregorian%20telescope

MLA

“Gregorian telescope.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Gregorian%20telescope. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Gregorian telescope,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Gregorian%20telescope.

Source: Gregorian telescope on Wiktionary, CC BY-SA 4.0.