Solar rotational mode splitting ($\delta {\omega }_{n\ell m}\simeq m\int K_{n\ell m}\Omega dV$)

Slow stellar rotation breaks the azimuthal degeneracy of a stellar oscillation. First-order rotational frequency shifts are weighted integrals of the angular velocity with kernels computed from the unperturbed mode. Multiple radial orders and angular degrees provide overlapping constraints on internal rotation. Surface rotation alone cannot replace these internal measurements, and a finite kernel set does not give pointwise uniqueness.