  Properties of magnon modes localized on a ferromagnetic skyrmion are studied.
Three types of possible asymptotic behavior of the modes eigenfrequencies are
found for the case of large skyrmion radius $R_s$, namely $\omega_0\sim
R_s^{-2}$ for the breathing mode, $\omega_{-|\mu|}\sim R_s^{-1}$ and
$\omega_{|\mu|}\sim R_s^{-3}$ for modes with negative and positive azimuthal
quantum numbers, respectively. A number of properties of the magnon
eigenfunctions are determined. This enables us to demonstrate that the skyrmion
dynamics based on the traveling wave model is described by the massless Thiele
equation.
