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

When Dr Koechlin and his team pointed it at Mars they could distinguish that planet’s two tiny moons—a task which would require a Newtonian telescope with a mirror at least 30cm across.

From Economist

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

From Project Gutenberg

The twenty-foot Newtonian telescope is a marvel; and there sits Caroline, as of old, writing down calculations and observations.

From Project Gutenberg

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 Project Gutenberg

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

From Project Gutenberg