  While the event horizon of a black hole could cast a shadow that was observed
recently, a central singularity without horizon could also give rise to such a
feature. This leaves us with a question on the nature of the supermassive black
holes at the galactic centers, and if they admit an event horizon necessarily.
We point out that observations of motion of stars around the galactic center
should give a clear idea of the nature of this central supermassive object. We
examine and discuss here recent developments that indicate intriguing behavior
of the star motions that could possibly distinguish the existence or otherwise
of an event horizon at the galactic center. We compare the motion of the S2
star with these theoretical results, fitting the observational data with
theory, and it is seen that the star motions and precession of their orbits
around the galactic center provide important clues on the nature of this
central compact object.
