  Observed hyperbolic minor bodies might have an interstellar origin, but they
can be natives of the Solar system as well. Fly-bys with the known planets or
the Sun may result in the hyperbolic ejection of an originally bound minor
body; in addition, members of the Oort cloud could be forced to follow inbound
hyperbolic paths as a result of secular perturbations induced by the Galactic
disc or, less frequently, due to impulsive interactions with passing stars.
These four processes must leave distinctive signatures in the distribution of
radiants of observed hyperbolic objects, both in terms of coordinates and
velocity. Here, we perform a systematic numerical exploration of the past
orbital evolution of known hyperbolic minor bodies using a full N-body approach
and statistical analyses to study their radiants. Our results confirm the
theoretical expectations that strong anisotropies are present in the data. We
also identify a statistically significant overdensity of high-speed radiants
towards the constellation of Gemini that could be due to the closest and most
recent known fly-by of a star to the Solar system, that of the so-called
Scholz's star. In addition to and besides 1I/2017 U1 (`Oumuamua), we single out
eight candidate interstellar comets based on their radiants' velocities.
