The Powers of a Telescope (II)
2. Resolving power:
Wave nature of light => The telescope aperture produces fringe rings that set a
limit to the resolution of the telescope.
amin = 1.22 (l/D)
Astronomers can’t eliminate these diffraction fringes,
but the larger a telescope is in diameter, the smaller the diffraction fringes
are. Thus the larger the telescope, the better its resolving power.
For optical wavelengths, this gives
amin = 11.6 arcsec / D[cm]
amin
