Telescopes

9.6 Telescopes:

1. Optical      Radio       IR      UV        X-ray

2. Refractive vs reflective     Spherical and chromatic aberrations     Transparency window for  ground based telescopes     Electromagnetic  pollution     Density and temperature fluctuation - 1 arcsec limit or better by  adaptive optics         Diffraction limit for the angular resolution

3. Detection of photons     Quantum efficiency      CCD

• Spectral resolution (energy/wavelength/frequency)

• Spatial resolution is measuring direction of motion 

• Temporal resolution is measuring arrival time (pulsars)

• Polarization