  Stars are massive resonators that may be used as gravitational-wave (GW)
detectors with isotropic sensitivity. New insights on stellar physics are being
made possible by asteroseismology, the study of stars by the observation of
their natural oscillations. The continuous monitoring of oscillation modes in
stars of different masses and sizes (e.g., as carried out by NASA's Kepler
mission) opens the possibility of surveying the local Universe for GW
radiation. Red-giant stars are of particular interest in this regard. Since the
mean separation between red giants in open clusters is small (a few light
years), this can in principle be used to look for the same GW imprint on the
oscillation modes of different stars as a GW propagates across the cluster.
Furthermore, the frequency range probed by oscillations in red giants
complements the capabilities of the planned eLISA space interferometer. We
propose asteroseismology of red giants as a novel approach in the search for
gravitational waves.
