ASTR 001 Lecture Notes - Lecture 7: Adaptive Optics, Angular Distance, Eyepiece
Document Summary
Two properties: hotter objects emit more light at all frequencies per unit area, hotter objects emit photons with a higher average energy. We need to (cid:271)e a(cid:271)le to (cid:862)(cid:271)end(cid:863) light to send it where we want it. Light from a far-away source comes in parallel and at an angle from an extended obect. The simplest, best- known telescope uses two lenses; one (the objective) is large to collect as much light as possible, and the other (the eyepiece) takes the focused light from the first and produces an image. The magnification of this kind of telescope is just the focal length of the objective divided by the focal length of the eyepiece. Hard to make without impurities which scatter light. Telescopes collect more light than our eyes. Telescopes can see more detail than our eyes. Telescopes/instruments can detect light that is invisible to our eyes (e. g. , infrared, ultraviolet) The minimum angular separation that the telescope can distinguish.
