9.1 Telescopes

• The magnification of a telescope is determined by the ratio of the focal lengths of the objective lens (or primary mirror) and the eyepiece
• What type of secondary mirror is used in a Cassegrain telescope?

  Convex
• Match the mounting type with its characteristic:

  Equatorial mounting ↔️ Aligned with Earth's axis

  Altazimuth mounting ↔️ Moves in altitude and azimuth
• Refracting telescopes are more compact and easier to align, but they suffer from chromatic aberration.
• What is the purpose of the objective lens in a refracting telescope?

  Collects and focuses light
• There are two main types of telescopes: refracting and reflecting.
• Match the type of telescope with an example:

  Refracting ↔️ Galilean

  Reflecting ↔️ Newtonian
• Reflecting telescopes use mirrors to focus light.
• What do reflecting telescopes use to focus light?

  Mirrors
• The primary mirror in a reflecting telescope is concave.

  True
• The primary mirror in a reflecting telescope is concave.

  True
• The tube of a reflecting telescope houses and aligns the primary and secondary mirrors.


  True
• A telescope is used to observe planets, stars, galaxies, and other celestial phenomena
• Reflecting telescopes can be made larger than refracting telescopes because lenses have size limitations.

  True
• Reflecting telescopes do not suffer from chromatic aberration.


  True
• The objective lens in a refracting telescope is located at the front of the telescope.


  True
• Match the primary optic with the telescope type:

  Refracting Telescope ↔️ Objective lens

  Reflecting Telescope ↔️ Primary mirror
• What is the primary mirror in a reflecting telescope?

  Large concave mirror
• What is a telescope used for?

  Magnify and resolve objects
• What limits the size of refracting telescopes?

  Size of lenses
• A telescope's purpose is to observe celestial phenomena too faint to see with the naked eye.


  True
• Which type of telescope does not suffer from chromatic aberration?

  Reflecting
• What is the function of the tube in a refracting telescope?

  Align lenses
• The main components of a reflecting telescope are the primary mirror, secondary mirror, focal length, and tube
• The focal length of a reflecting telescope is the distance between the primary mirror and the point where light converges to form an image
• What is the purpose of a telescope?

  Magnify and resolve distant objects
• Refracting telescopes suffer from chromatic aberration
• What are examples of refracting telescopes?

  Galilean and Keplerian
• The main components of a refracting telescope are the objective lens, eyepiece lens, focal length, and tube
• The tube of a refracting telescope houses and aligns the lenses.


  True
• Reflecting telescopes use mirrors to focus light.


  True
• Match the primary optic with its telescope type:

  Refracting telescope ↔️ Objective lens

  Reflecting telescope ↔️ Primary mirror
• Order the properties based on their relationships:

  1️⃣ Magnification increases with larger objective lens/mirror and smaller eyepiece lens

  2️⃣ Resolution increases with larger objective lens/mirror diameter
• Cassegrain telescopes are generally more compact than Newtonian telescopes but also more expensive
• Refracting telescopes use lenses to focus light, while reflecting telescopes use mirrors.


  True
• The focal length in a refracting telescope is the distance between the objective lens and the point where light converges to form an image.


  True
• The tube of a refracting telescope houses and aligns the objective and eyepiece lenses.

  True
• The secondary optic in a reflecting telescope is the secondary mirror.


  True
• Refracting telescopes use lenses to focus light.


  True
• What optical defect do refracting telescopes suffer from?

  Chromatic aberration