Atomic ions and free electrons embedded in condensed helium play important role in modern research on quantum fluids and solids. Here we present experimental and theoretical study of Ba+ cations immersed in superfluid He. We observe laser-induced fluorescence of Ba+ injected into liquid He from the plasma of radio frequency discharge in He-Ba gas mixture. The structure of trapping site is studied theoretically in the frame of the atomic bubble model making use of ab initio Ba+ - He pair potentials available in the literature. Calculated spectra of the ion are compared with the results of the experiment