Newtonian telescope

American  

noun

1. a reflecting telescope in which a mirror or reflecting prism is mounted on the axis near the eyepiece so that the image may be viewed from outside the telescope tube at right angles to the axis.

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Newtonian telescope British  

noun

1. a type of astronomical reflecting telescope in which light is reflected from a large concave mirror, onto a plane mirror, and through a hole in the side of the body of the telescope to form an image

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Etymology

Origin of Newtonian telescope

First recorded in 1755–65

Example Sentences

This instrument is a Newtonian telescope connected to a UV-sensitive camera.

From Science Daily • Apr. 21, 2026

He has his twenty-foot Newtonian telescope in the open air and mounted in his garden very simply and conveniently.

From Sir William Herschel: His Life and Works by Holden, Edward Singleton

Her chief amusement during her leisure hours was sweeping the heavens with a small Newtonian telescope.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 4 "Hero" to "Hindu Chronology" by Various

He has his 20-foot Newtonian telescope in the open air, and mounted in his garden very simply and conveniently.

From Pioneers of Science by Lodge, Oliver, Sir

The first was made with a Newtonian telescope something less than seven feet focal length, a power of 222, and an aperture of four and a half inches.

From Sir William Herschel: His Life and Works by Holden, Edward Singleton