Question

Which type of telescope focuses star light using mirrors?

Answer 1

Reflecting telescopes, also known as reflectors, focus starlight using mirrors. The main optical element in a reflecting telescope is a concave mirror, which reflects light and forms an image at the focus. Reflecting telescopes have different options for bringing the light to a focus, such as the Cassegrain focus.

Step-by-step explanation:

Reflecting telescopes, also known as reflectors, focus starlight using mirrors.

The main optical element in a reflecting telescope is a concave mirror, which is curved like the inner surface of a sphere. This mirror reflects light and forms an image at the focus of the mirror. The mirror is coated with a shiny metal, such as silver, aluminum, or occasionally gold, to make it highly reflective.

Reflecting telescopes have different options for where the light is brought to a focus. For example, with a Cassegrain focus, light is reflected by a secondary mirror down through a hole in the primary mirror to an observing station below the telescope.

Answer 2

Coudé telescopes use a convex secondary mirror like a Cassegrain and an angled mirror like a Newtonian reflector to move the light rays to a focal point away from the telescope. This arrangement is useful when optical equipment is being used that is too heavy to mount directly on the telescope.