1. Lecture 7 – September 10, 2003 Telescopes
What have you been looking through these nights?
Progress in astronomy would have been impossible without them

2. Telescopes do two things:
Collect “Big Piles” of light
Magnify object (it looks a lot closer than it is)

3. Types of Telescopes Refractors Reflectors Radio telescopes
None of the above

5. Reflectors and Refractors
Newtonian
Cassegrain

6. Resolution: How small detail can you see with a telescope?

7. Resolution: smallest angle measurable
Angle=wavelength/diameter(telescope)
(radians)

8. Wavelength large (1cm – 1 meter typically) so D has to be HUGE
Radio Telescopes
Wavelength large (1cm – 1 meter typically) so D has to be HUGE

9. Radio Interferometers:
The ultimate in angular resolution