PX285 - F2 - visual binaries

both components can be seen and tracked
considering near-circular orbits, using kelper's law:

M_{1} r_{1} = M_{2} r_{2}

balancing the gravitational and centripetal forces gives:

M_{1} + M_{2} = \frac{4 π^{2}}{G} \frac{(r_{1} + r_{2})^{3}}{P^{2}}