Using the relationship between density, mass and volume to solve for
the Star's mass
Density is the amount of matter in a given volume. Density is a
characteristic property of matter. This means that density can
be used to identify a sample of matter and the size of your sample will
not change your result. Density is determined by dividing the mass of a
substance by the volume occupied by that mass.
If you know the volume and density of an object, a simple rearrangement
of the above equation wil let you calculate it's mass.