  Bright fireballs or bolides are caused by meteoroids entering the Earth's
atmosphere at high speed. On 2013 February 15, a superbolide was observed in
the skies near Chelyabinsk, Russia. Such a meteor could be the result of the
decay of an asteroid and here we explore this possibility applying a multistep
approach. First, we use available data and Monte Carlo optimization (validated
using 2008 TC3 as template) to obtain a robust solution for the pre-impact
orbit of the Chelyabinsk impactor (semimajor axis = 1.62 au, eccentricity =
0.53, inclination = 3.82 deg, longitude of the ascending node = 326.41 deg and
argument of perihelion = 109.44 deg). Then, we use this most probable orbit and
numerical analysis to single out candidates for membership in, what we call,
the Chelyabinsk asteroid family. Finally, we perform N-body simulations to
either confirm or reject any dynamical connection between candidates and
impactor. We find reliable statistical evidence on the existence of the
Chelyabinsk cluster. It appears to include multiple small asteroids and two
relatively large members: 2007 BD7 and 2011 EO40. The most probable parent body
for the Chelyabinsk superbolide is 2011 EO40. The orbits of these objects are
quite perturbed as they experience close encounters not only with the
Earth-Moon system but also with Venus, Mars and Ceres. Under such conditions,
the cluster cannot be older than about 20-40 kyr.
