  Stellar prominences detected in rapidly rotating stars serve as probes of the
magnetism in the corona of cool stars. We have synthesized the temporal
evolution of the Stokes profiles generated in the He I 10830 and 5876 A
triplets during the rotation of a prominence around a star. The synthesis was
performed with the HAZEL code using a cloud model in which the prominence is
characterized by a slab located at a fixed latitude and height. It accounts for
the scattering polarization and Zeeman and Hanle effects. Several cases with
different prominence magnetic field strengths and orientations have been
analyzed. The results show an emission feature that drifts across the profile
while the prominence is out of the stellar disk. When the prominence eclipses
the star, the intensity profile shows an absorption. The scattering induced by
the prominence generates linear polarization signals in Stokes Q and U
profiles, which are modified by the Hanle effect when a magnetic field is
present. Due to the Zeeman effect, Stokes V profiles show a signal with very
low amplitude when the magnetic field along the line-of-sight is different from
zero. The estimated linear polarization signals could potentially be detected
with the future spectropolarimeter MIRADAS, to be attached to GTC telescope.
