  We study the implications on compact star properties of a soft nuclear
equation of state determined from kaon production at subthreshold energies in
heavy-ion collisions. On one hand, we apply these results to study radii and
moments of inertia of light neutron stars. Heavy-ion data provides constraints
on nuclear matter at densities relevant for those stars and, in particular, to
the density dependence of the symmetry energy of nuclear matter. On the other
hand, we derive a limit for the highest allowed neutron star mass of three
solar masses. For that purpose, we use the information on the nucleon potential
obtained from the analysis of the heavy-ion data combined with causality on the
nuclear equation of state.
