<span>The absolute magnitude of a star is how bright it would appear to us
if it were located ten parsecs (about 32.6 light years) from us. So it's
a way of treating all stars equally ... on a "level playing field" ... and it
describes each star's actual brightness. </span>
All of them apply because they all are doing some thing to move

We would calculate the magnitude by applying pythagorean theorem:



The angle between two vectors is given by the formula:

In two dimensional, the x axis of vector form is:







