THE BEEHIVE OBSERVATORY

Just the Dawes and Rayleigh limits to resolving power and usual limiting magnitude formula. Of course, the magnitude limit is for visual observations only.

Here is a C language version...

   // DawesLimit(ObjectiveDiameter (m))
   // Returns a measure of resolving power in radians.
   // S = 4.56 / D (D in inches, S in arcsec)
   double astro_DawesLimit(double ObjectiveDiameter)
   {
      return astro_RadiansFromArcSec((4.56 * 2.54) / ObjectiveDiameter / 100.0);
   }

   // S = 5.45 / D
   double astro_RayleighLimit(double ObjectiveDiameter)
   {
   return astro_RadiansFromArcSec((5.45 * 2.54)/ ObjectiveDiameter / 100.0);
   }

   // M = 9.1 + 5 ln D (where D is in inches) this is the theoretical
   // limit for a standard eye (pupil 7.5 mm) etc. and an eyepiece that
   // has a small enough exit pupil. Seeing is mag 6.5 naked eye. Metres.
   double astro_LimitingMagnitude(double ObjectiveDiameter)
   {
      return 9.1 + 5.0 * Log10(ObjectiveDiameter * 100.0 / 2.54);
   }