The Telescope

The Telescope (CCU)

Unit 3: Telescopes (weeks 6-8)

Major theme: Astronomy is an observational, not an experimental science.

Learning Objectives:

  • Outline the main functions of a telescope (light-gathering power, resolution, and magnifying power) and relate each to a telescope’s design.
  • Compare and contrast reflection and refracting telescopes; include a sketch of the optical layout of each in your comparison.
  • Compare a radio telescope to an optical telescope in terms of functions, design, and use.
  • Describe what is meant by the term invisible astronomy.
  • Contrast an infrared telescope to an optical telescope in terms of functions, design, and use.
  • Discuss at least two important advantages a space telescope in earth orbit has over a ground-based telescope.


Physics of optics/light

  • Reflection
  • Refraction
  • Electromagnetic Spectrum
  • Spectroscopy

Optical telescope design

  • Refracting telescopes
  • Reflecting telescopes: Primary Focus, Newtonian, & Cassegrain

Properties, Function, and Limitations of Telescope

  • Light-gathering power
  • Resolving fine detail
  • Magnification
  • Interferometry
  • Chromatic & Spherical Aberration

Invisible Astronomy (the dawn of Multi-wavelength Astronomy)

  • Atmospheric distortion and light pollution
  • Radio astronomy
  • Infrared telescopes
  • X-Ray space-based observatories

Class Notes

Telescopes – All Notes

Reflection & Refraction Notes

Spectrum Notes

Telescope Notes

Read Zeilik: Chapter 6

Useful websites: 

Discovery Channel’s – Telescope (2016)

UT Quest Homework

Star Chart of the Month

Sky at a Glance

In the Sky this Month

Scale of the Universe

Online Astronomy:

How to choose a good telescope