Definition

Noun: A Newtonian reflector is a type of reflecting telescope. Its key design feature is that the image is viewed through an eyepiece that is positioned at a right angle (perpendicular) to the telescope's main optical axis. This is achieved using a small, flat secondary mirror to redirect the light gathered by the primary mirror out to the side of the tube.

Usage

The term is used specifically to describe this particular optical design of a telescope, distinguishing it from other types like refractors or Cassegrain reflectors. - For amateur astronomers, a Newtonian reflector often offers the best value for aperture size. - The classic Newtonian reflector design was invented by Sir Isaac Newton in 1668.

Advanced Usage

• The design is often praised for its simplicity and lack of chromatic aberration, as it uses mirrors instead of lenses to gather and focus light.
• The term can be used in technical discussions about optical engineering, amateur telescope making, and observational astronomy.

Variants and Related Words

• Newtonian telescope: A direct synonym for Newtonian reflector.
• Reflector: A broader category of telescopes that use mirrors, which includes the Newtonian design as well as others like Cassegrain and Gregorian reflectors.
• Refracting telescope (Refractor): A different type of telescope that uses lenses instead of mirrors, providing a contrast to the reflecting design.

Synonyms

• Newtonian telescope

Antonyms

• Refracting telescope (in the context of the fundamental optical design principle)

Noun

1. reflecting telescope in which the image is viewed through an eyepiece perpendicular to main axis