  We consider circular motion of a heavy object in an atomic Bose-Einstein
condensate (BEC) at $T=0{\rm K}$. Even if the linear velocity of the object is
smaller than the Landau critical velocity, the object may radiate
quasiparticles and thus experience the quantum friction. The radiation process
is similar to Zel'dovich-Starobinskii (ZS) effect -- the radiation by a
rotating black hole. This analogy emerges when one introduces the effective
acoustic metric for quasiparticles. In the rotating frame this metric has an
ergosurface, which is similar to the ergosurface in the metric of a rotating
black hole. In a finite size BEC, the quasiparticle creation takes place when
the ergosurface is within the condensate and occurs via quantum tunneling from
the object into the ergoregion. The dependence of the radiation rate on the
position of the ergosurface is investigated.
