We revisit the determination of binary mass ratio in the Galactic microquasar SS433 based on recent GRAVITY VLTI measurements of mass and angular momentum outflow through a circumbinary disc .
The new observations combined with the constancy of the binary orbital period over \sim 30 yrs confirm that the mass ratio in SS433 is q = M _ { \mathrm { x } } / M _ { \mathrm { v } } \gtrsim 0.6 .
For the assumed optical star mass M _ { \mathrm { v } } ranging from \sim 8 to 15 M _ { \odot } such a mass ratio suggests a low limit of the compact object mass of M _ { \mathrm { x } } \sim 5 - 9 M _ { \odot } , placing the compact object in SS433 as a stellar-mass black hole .