Dynamics of the star S0-1 and the nature of the compact dark object at theGalactic center

It has recently been shown that analysis of the orbits of the fast-moving s tars close to Sgr A* provides a valuable tool to probe the gravitational po tential near the Galactic center. As an example, we present here the result s of a calculation of possible orbits of the star S0-1 in both the black ho le and the degenerate neutrino ball scenarios of the central mass, based on the recent measurements of stellar proper motions at the Galactic center b y Ghez et al. Taking into account the error bars of their analysis, it is s hown that within a few years, the orbit of S0-1 may indeed reveal the natur e of the supermassive compact dark object at the Galactic center.