The authors demonstrate in this work that there is a peculiar source of low-frequency photon emission when a slow massive charged particle collides with an excited hydrogen atom. This radiation is generated by the rotating dipole moment of the hydrogen during the collision. The specific feature of the problem is in the appearance of the dipole moment of the excited hydrogen due to mixing of degenerated levels with different parity in the field of the projectile particle (linear Stark effect). The radiation associated with transitions between components of the Stark multiplet is also considered. Its contribution to the total radiation spectrum is shown to be important.