Question

Procyon, a 1.5 solar mass main sequence star, has a white dwarf companion of mass 0.6 solar masses. They orbit each other with a period of 40.82 years. What is the distance between the two stars in au?

Answer 1

From Newton's form of Kepler's third law,

where and are the masses of the respective stars. if masses are in unit of solar masses and time is in unit of years then Separation distance is automatically in units of AU.

now

or

or