  The existence of a massive black hole in the center of the Milky Way,
coinciding with the radio source Sgr A*, is being established on more and more
solid ground. In principle, this black hole, acting as a gravitational lens, is
able to bend the light emitted by stars moving within its neighborhood,
eventually generating secondary images. Extending a previous analysis of the
gravitational lensing phenomenology to a new set of 28 stars, whose orbits have
been well determined by recent observations, we have calculated all the
properties of their secondary images, including time and magnitude of their
luminosity peaks and their angular distances from the central black hole. The
best lensing candidate is represented by the star S6, since the magnitude of
its secondary image at the peak reaches K=20.8, with an angular separation of
0.3 mas from the central black hole, that is just at the borders of the
resolution limit in the K band of incoming astronomical instruments.
