Ya. B. Zeldovich All-Moscow Seminar of Astrophysicists

It is generally accepted now that there is a supermassive black hole

at the Galactic Center. We review observational studies  to prove

the claim about a black hole existence at the Galactic Center.

Observations of trajectories of bright stars at the Galactic Center

in IR band have been done with an enormous precision. Two groups of

people led by R. Genzel (Germany) and A. Ghez (USA) done the

observations in IR band with the largest optical telescopes and as a

result in 2012 R. Genzel and A. Ghez were awarded  by the Crafoord

prize. We discuss theoretical studies connected with the

observations. A great progress of the Galactic center has been done

with VLBI observations in mm band. We review theoretical studies and

their links with observations to get constraints on parameters of

the Galactic Center potential and as a result to evaluate parameters

of the black hole and distributions of stellar cluster and dark

matter near the black hole.