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.
MOA stands for Minute Of Angle. A full circle is divided into 360 degrees and each degree is divided into 60 minutes. Thus, there are 21,600 minutes in a full circle (360 x 60 = 21,600). A minute is a small angle, but it's exactly what's needed for gun sights. A rule of thumb is that changing a sight's elevation setting by 1 minute of angle changes the bullet's impact point by 1 inch at 100 yards. A more exact value and how it's arrived at is shown below: