1. Light, Optics and Telescopes The Electromagnetic Spectrum

2. Photons of different energies radiate at different wavelengths or frequencies wavelength x frequency = velocity of light ( c)  = c The Inverse Square Law of Radiation

3. Atmospheric Windows Visible and radio

4. Physical Properties of Light Refraction

5. Reflection Refraction is wavelength dependent

6. Formation of an image

7. Telescopes -- Refractors Yerkes Observatory – Lake Geneva, Williams Bay Wisconsin

8. Properties of the telescope Collecting Area -- diameter squared (D 2 ) Resolution or Resolving Power - wavelength/diameter ( /D) Limitations -- Atmospheric -- weather “seeing” -- turbulence

10. 20 th Century Large Reflectors Mt Wilson 100-inch – 100 yrs old Cerro Tololo 4 -meter Palomar 200-inch

11. Modern Observatories Cerro Tololo Interamerican Obs.

12. Kitt Peak National Obs. Tucson Arizona

13. MMT on Mt. Hopkins, AZ

14. Very Large Telescopes Mauna Kea ESO – VLT

15. Minnesota’s $5M (private) investment in a very large telescope (> $100M) Large Binocular Telescope (LBT) Mt. Graham Arizona Design Other partners -- University of Arizona, Germany, Italy, Ohio State University, University of Virginia, Notre Dame

16. Astronomical Instruments Cameras/Imagers -- pictures, Photometers – brightness and colors Spectrographs -- the spectrum, energy vs. wavelength. Doppler Effect – any wave motion Away – longer  lower Toward – shorter, higher Redshift Blueshift

17. Radio Telescopes

18. Arecibo Very Large Array – VLA

19. Telescopes in Space -- other wavelengths – UV, X ray, gamma ray and far-IR