Forbidden Emission Lines of Mn I and Fe II in the Spectra of Long-Period Variables Near Minimum Light.

The behavior of the emission-line intensities of Mn I and [Mn I] in spectra of the long-period variable x Cygni is discussed. Departures from a statistical distribution of the metastable levels occur in the cases of neutral manganese and singly ionized iron, as seen from relative intensities of [Mn ii and [Fe iii lines in the spectra of several Mira variables near minimum light. The magnetic dipole and electric quadrupole transition probabilities are computed for the configurations 3d54s and 3d64s of Mn I.