Astrophysics

• Telescopes

  • Gather far more light than the eye
  • We can see dim objects as enlarged and much clearer
• Image formation in a telescope

  1. Arrangement of lenses

  2. Can produce upright or inverted images
• Telescope components

  • Concave eyepiece lens - focuses the light
  • Convex objective lens - gathers light from distant objects
• The eyepiece lens of a telescope is a concave lens and focuses the light into the eye
• Why we can see distant objects more clearly with a telescope

  A telescope gathers more light
• Magnification

  Ratio between how large an object is without a lens and how large it is with a lens
• Subtended angle

  The angle from a line to the middle of the object and a line to the top of an object from the eye
• M= f ₀ divided by f ₑ