  Constraints to the mass of a scalar field and the strength of its
self-interacting coupling constant are obtained. This was done using
observations of stellar dynamics at the center of our galaxy and by assuming
that the dark compact object responsible of such dynamics is a boson star and
not a supermassive black hole. We show that if such scalar field represents a
spin-zero particle with cross section high enough to be considered collisional
dark matter, there is a region of parameters compatible with both conditions:
that the scalar field play the role of collisional dark matter and that it can
form objects with the mass and compactness compatible with stellar kinematics.
