IUE observations of proto-planetary and variable planetary nebulae. II. A search for variability in IC 4997 and NGC 6905.

A search for ultraviolet variability was conducted for the planetary nebulae IC 4997 and NGC 6905 which have histories of variability in the visible region. Emission line fluxes, line ratios, line profiles, and central stars' temperatures are presented for both objects, as well as stratification effects for several ions in NGC 6905.