Formulae. 1  Eclipsing binary: diameter = speed Ã time of eclipse. 2  Size from luminosity: star's radius/Sun's radius = (Sun's temperature/star's temperature)2 Sqrt[star's luminosity/Sun's luminosity].
MOA is a mathmatical concept that most firearm scopes incorporate. Minute of Angle (MOA) is critical to sighting in your scope. MOA mathematical concepts were used to develop the AccuScope scope sighting reference tool. The only MOA information needed to use AccuScope is your scope's MOA number.
The best way I can think of to understand MOA at distance is to think of a laser pointer run through the barrel of your rifle. If you began with the laser dot on the center of the X-ring of a target standing at 100 yards and the barrel angle was increased 1 MOA, the dot would then be about one inch high at 100 yards.