Reflecting telescope

Definition

A reflecting telescope uses mirrors to gather and focus light. It was invented by Isaac Newton and is widely used in both amateur and professional astronomy.

5 Must Know Facts For Your Next Test

1. Reflecting telescopes use a primary concave mirror to collect light.
2. They do not suffer from chromatic aberration because mirrors reflect all wavelengths of light equally.
3. The most common design is the Newtonian reflector, which includes a secondary diagonal mirror that directs light to an eyepiece on the side of the telescope.
4. Large modern astronomical observatories often use reflecting telescopes due to their ability to be scaled up in size more easily than refracting telescopes.
5. Reflecting telescopes can have various designs such as Cassegrain, Gregorian, and Ritchey-Chrétien configurations.

Review Questions

• What type of mirror does a reflecting telescope use to collect light?
• Why do reflecting telescopes not suffer from chromatic aberration?
• Name one advantage of using a reflecting telescope over a refracting telescope.

Related terms

Refracting Telescope:

A type of telescope that uses lenses to form an image.

Newtonian Reflector: A type of reflecting telescope designed by Isaac Newton that uses a concave primary mirror and a flat diagonal secondary mirror.

Chromatic Aberration:

An optical issue where different colors of light are focused at different points due to dispersion through lenses.