  The universe is expected to be permeated by a stochastic background of
gravitational radiation of astrophysical and cosmological origin. This
background is capable of exciting oscillations in solar-like stars. Here we
show that solar-like oscillators can be employed as giant hydrodynamical
detectors for such a background in the muHz to mHz frequency range, which has
remained essentially unexplored until today. We demonstrate this approach by
using high-precision radial velocity data for the Sun to constrain the
normalized energy density of the stochastic gravitational-wave background
around 0.11 mHz. These results open up the possibility for asteroseismic
missions like CoRoT and Kepler to probe fundamental physics.
