THE POSSIBILITY OF TRANSITION RADIATION IN PLANETARY-NEBULAE

A new concept -'the'Paradox of Nebula IC 4997'- is the main subject of the present article. The essence of this paradox arises when the variations of the intensities of forbidden lines 4363 [O III] and N1 + N2 [O III] take place not in unison as is predicted by the classical theory. An attempt is made to solve this paradox, suggesting the possibility both of spontaneous appearance of relativistic electrons in the nebula and the generation of so-called transition radiation as a result of electrodynamic interaction of these electrons with dust particles in nebula. The parameters of relativistic electrons and power of transition radiation are obtained. The problems which need further examination are also enumerated.