Q:  What is the initial total energy of the system?
            (KE of each star, plus GPE of the two stars)



        KE_A  =   0.5 * ( 5.97 x 10^(30) kg ) * ( 6.91 x 10^4 m/s )^2

              =   1.43 x 10^(40) J


        KE_B  =   0.5 * ( 1.99 x 10^(30) kg ) * ( 1.20 x 10^5 m/s )^2

              =   1.43 x 10^(40) J

 
                   (Hmmm.  The two stars have the same KE ...)

                         G * M_A * M_B
        GPE   =    -   ---------------------
                          1.39 x 10^(10) m


              =    -  5.70 x 10^(40) J



       initial total energy  =  KE_A  +  KE_B   +  GPE

                             =   - 2.85 x 10^(40) J